JP2022027680A - Photoelectric conversion semiconductor device - Google Patents

Abstract

To improve the efficiency of photoelectric conversion.SOLUTION: In the depth direction of a photoelectric conversion semiconductor device 1, front and back sides of an N region 4 are sandwiched between P regions 3, 5, and furthermore, the front side of the P region 3 and the back side of the P region 5 are sandwiched between P+ region 2 and P+ region 6 for concentration gradient type barrier electric field generation to form a P+PNPP+ junction 7. A photosensitive window region 8 and an outer electrode 9 of a first polarity are provided on the front side of the P+ region 2, and an outer electrode 10 of a first polarity is provided on the back side of the P+ region 6. An N+ region 11 for photoelectron absorption is provided in the center of the depth direction of an N region 4, and an outer surface electrode 12 of a second polarity is provided on the outside of the N+ region 11. The outer surface electrodes 9, 10 of the first polarity are connected to ground, and a capacitance 30 for charge storage is connected between an outer surface electrode 12 of the second polarity and ground.SELECTED DRAWING: Figure 1

Description

The present invention relates to a photoelectric conversion semiconductor device, and more particularly to a photoelectric conversion semiconductor device in which energy conversion efficiency is improved by suppressing recoupling of photoelectrons generated in the photoelectric conversion semiconductor device.

Photovoltaic power generation is attracting attention as a natural energy source that suppresses global warming. The solar power generation has a PN junction in which an N-type semiconductor region and a P-type semiconductor region are adjacent to each other, and a PN junction type barrier electric field in which photoelectrons and holes generated by light irradiation are generated in a poor layer of the PN junction, respectively. The N-type semiconductor region side and the P-type semiconductor region side are separated by A photoelectric conversion semiconductor device capable of generating electric power is used.
By the way, the energy density of solar power is low, and a large-scale facility is required to increase the amount of power generation. Therefore, further improvement of the conversion efficiency of solar cells is important for the spread of photovoltaic power generation.

As one of the measures for improving the conversion efficiency, conventionally, as shown in JP-A-53-10987 and JP-A-07-297444, for example, the PN junction surface parallel to the surface of the photoelectric conversion semiconductor device is formed in the depth direction (up and down). A method of forming a plurality of pieces in the direction) has been proposed.
However, in the photoelectric conversion semiconductor device of JP-A-53-10987 and JP-A-07-297444 described above, photoelectrons move to a place having a low energy level in the N region and stay there, but the staying photoelectrons The potential of the N region fluctuates without being fixed according to the amount of the Bonding is likely to occur, and there is a limit to the improvement of conversion efficiency.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a photoelectric conversion semiconductor device in which the conversion efficiency of photoelectric conversion is improved.

In the invention according to claim 1,
A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
Inside the photoelectric conversion semiconductor device, both the front and back sides of the N region are sandwiched between the front side P region and the back side P region in the depth direction from the front side to the back side, and the front side and the back side of the back side P region of the front side P region are further sandwiched. , A P + PNPP + junction sandwiched between the P + region on the front side and the P + region on the back side for generating a concentration gradient type barrier electric field generated by the concentration gradient of P + P is provided.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided at the center of the N region in the depth direction so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided outside the N + region.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
It is characterized by.
In the invention according to claim 2,
A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
An N region is provided in the photoelectric conversion semiconductor device, and
A P region is provided so as to surround the front side, the back side, and the side surface side except for a part near the left and right ends on the back side of the N region.
On the front side of the P region, a P + region on the front side is provided so as to be in contact with the surface of the P region.
On the back side of the P region, a P + region on the back side is provided so as to be in contact with the surface of the P region.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided near the left and right ends on the back side of the N region so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided on the back side of the N + region.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
It is characterized by.
In the invention according to claim 3,
A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
A P region is provided so as to surround the front side, the back side, and the side surface side excluding the back side central portion of the N region provided in the photoelectric conversion semiconductor device.
On the front side of the P region, a P + region on the front side is provided so as to be in contact with the surface of the P region.
On the back side of the P region, a P + region on the back side is provided so as to be in contact with the surface of the P region.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided in the central portion on the back side of the N region so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided on the back side of the N + region.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
It is characterized by.
In the invention according to claim 4,
It is a photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the surface side.
A P region is provided so as to surround the front side and the side surface side excluding the back side of the N region having a comb-shaped cross section provided in the photoelectric conversion semiconductor device.
A P + region is provided on the front side of the P region so as to be in contact with the surface of the P region.
On the front side of the P + region, an outer surface electrode having a first polarity conducting with the light receiving window region and the surface of the P + region is provided.
An N + region for sucking photoelectrons is provided on the back side of the N region so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided on the back side of the N + region.
The outer electrode of the first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
It is characterized by.
In the invention according to claim 5,
A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
A P region is provided so as to surround the front side, the back side, and the side surface side excluding the back side central portion of the N region having a comb-shaped cross section provided in the photoelectric conversion semiconductor device.
On the front side of the P region, a P + region on the front side is provided so as to be in contact with the surface of the P region.
On the back side of the P region, a P + region on the back side is provided so as to be in contact with the surface of the P region.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided in the central portion on the back side of the N region so as to be in contact with the N region.
On the back side of the N + region, an outer surface electrode having a second polarity conducting with the N + region is provided.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
It is characterized by.
In the invention according to claim 6,
A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
A photoelectric conversion layer is provided in the photoelectric conversion semiconductor device, and the photoelectric conversion layer is provided.
This photoelectric conversion layer is
The N region provided in the photoelectric conversion semiconductor device and
On the front side excluding the central part of the front side of the N region, a P region on the front side provided in contact with the surface of the N region and a P region on the front side.
A P region on the back side provided on the back side of the N region so as to be in contact with the surface of the N region, and a P region on the back side.
All or part of the front side of the P region on the front side and the side surface side, the side surface side of the N region, and the P + region provided so as to surround the back side and the side surface side of the P region on the back side.
An N + region on the front side provided in contact with the N region at the center of the front side of the N region,
Including
On the front side of the photoelectric conversion unit, a light receiving window region, an outer surface electrode having a first polarity conducting with the surface of the P + region, and an outer surface electrode having a second polarity conducting with the N + region are provided.
A metal reflection region is provided on the back side of the P + region via at least one of the second N region and the second N + region.
The outer electrode of the first polarity and the metal reflection region are connected to the ground, and a charge storage capacity provided inside or outside the photoelectric conversion semiconductor device is provided between the outer electrode of the second polarity and the ground. Having connected,
It is characterized by.
In each claim, the N + region may be provided so as to be embedded in the N region.

According to the present invention, by sucking photoelectrons that have moved to a place where the energy level of the N region is low to the N + region, the depletion state of the N region is always maintained, and the depletion layer is prevented from narrowing. , It is possible to suppress the recombination of photoelectrons and vacancies. Further, the concentration gradient type barrier electric field generated by the concentration gradient of P + P can suppress recombination near the front surface and the back surface, and can improve the conversion efficiency.
In addition, since the surface of the P + region is fixed to the ground potential, it is less susceptible to disturbances such as surges, and the electric field near the surface of the P + region becomes zero, so that heat is generated near the surface of the P + region. Since the electrons that absorb energy and rise to the conduction band are immediately recombined with the vacancies on the spot, there is less risk of becoming a surface dark current and discharging the external or internal capacitance, further improving conversion efficiency. It can be improved.

FIG. 1 is an explanatory diagram showing a cross-sectional structure of a photoelectric conversion semiconductor device according to the first embodiment of the present invention, a configuration of an external circuit, and an impurity concentration profile (Example 1). FIG. 2 is an explanatory diagram showing an impurity concentration profile of the photoelectric conversion semiconductor device of FIG. FIG. 3 is an explanatory diagram showing an energy band in the depth direction of the P + PNPP + junction in FIG. 1. FIG. 4 is a configuration diagram showing a cross-sectional structure of a photoelectric conversion semiconductor device according to a second embodiment of the present invention and a configuration of an external circuit (Example 2). FIG. 5 is a configuration diagram showing a cross-sectional structure of a photoelectric conversion semiconductor device according to a third embodiment of the present invention and a configuration of an external circuit (Example 3). FIG. 6 is a configuration diagram showing a cross-sectional structure of a photoelectric conversion semiconductor device according to a fourth embodiment of the present invention and a configuration of an external circuit (Example 4). FIG. 7 is a configuration diagram showing a cross-sectional structure of a photoelectric conversion semiconductor device according to a fifth embodiment of the present invention and a configuration of an external circuit (Example 5). FIG. 8 is an explanatory diagram showing energy bands along various directions of the photoelectric conversion semiconductor device of FIG. 7. FIG. 9 is a configuration diagram showing a cross-sectional structure of a photoelectric conversion semiconductor device according to a sixth embodiment of the present invention and a configuration of an external circuit (Example 6). FIG. 10 is a configuration diagram showing a cross-sectional structure of a photoelectric conversion semiconductor device according to a seventh embodiment of the present invention and a configuration of an external circuit (Example 7).

Hereinafter, the best embodiment of the present invention will be described based on examples.

The photoelectric conversion semiconductor device according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3. 1 is an explanatory view showing a cross-sectional structure and an external circuit of a photoelectric conversion semiconductor device, FIG. 2 is an explanatory view showing a specific impurity concentration profile of the photoelectric conversion semiconductor device of FIG. 1, and FIG. 3 is a P + PNPP + junction portion in FIG. It is explanatory drawing which shows the energy band in the depth direction of. The energy level of photoelectrons is highest in the P + region on the front side and the back side of the photoelectric conversion semiconductor device, and lowest in the N + region.
In FIG. 1, 1 is a photoelectric conversion semiconductor device that receives sunlight and generates photovoltaic power, the right side is the front surface (light receiving main surface), the left side is the back surface, and the depth direction is from right to left. The direction to go. The P + region 2, the P region 3, the N region 4, the P region 5, and the P + region 6 are provided so as to be in contact with the front surface of the P + PNPP + joint portion 7 and the P + region 2 to which the P + region 6 is joined in multiple stages in the depth direction from the front surface. Insulating SiO2 region 8 and P + region 2 as a transparent light receiving window region are provided so as to be in contact with the back surface of the first polar outer electrode 9 and P + region 6 provided so as to be in contact with the front surface. The outer electrode 10 having the first polarity and the N + region 11 and the N + region 11 for photoelectron suction provided in an embedded state so as to be in contact with the central portion of the N region 4 in the depth direction are provided outside the N + region 11. It is provided with an outer surface electrode 12 having two polarities. Here, P regions 3 and 5 on the front side and the back side show an example in which the thickness in the depth direction is the same. The outer surface electrode 9 is conducting with the P + region 2, the outer surface electrode 10 is conducting with the P + region 6, and the outer surface electrode 12 is conducting with the N + region 11. The outer surface electrodes 9, 10 and 12 are made of metal.

The P + PNPP + joint portion 7 is formed substantially symmetrically in the front and back directions with the center of the N region 4 in the depth direction as the center. That is, both sides of the front and back sides of the N region 4 are sandwiched between the front side P region 3 and the back side P region 5, and the front and outer sides of the front side P region 3 and the back side of the back side P region are the concentrations generated by the concentration gradient of P + P. It is laminated by sandwiching it between the P + region 2 on the front side and the P + region 6 on the back side for generating a gradient type barrier electric field. The P region 3, the N region 4, and the P region 5 form a two-stage PN junction surface in the depth direction, and both the upper and lower sides (left and right in FIG. 1) sandwich the junction surface jk1 of the N region 4 and the P region 3. A PN junction type barrier electric field region generated in the depletion layer of the PN junction is formed on both the upper and lower sides (both left and right in FIG. 1) sandwiching the junction surface jk2 of the N region 4 and the P region 5 (both sides).

In order to suppress the recombination of photoelectrons near the front surface of the photoelectric conversion semiconductor device 1, the P + region 2 on the front side generates a concentration gradient type barrier electric field generated by the concentration gradient of P + P, and is photoelectric for a blue short wavelength optical component. This is an area provided to improve the conversion efficiency. Sunlight shows a large proportion of energy in the short wavelength region, but in silicon semiconductors, for example, blue short wavelength light can only pass through to a depth of about 0.2 μm from the surface. In this embodiment, the P + P concentration gradient type barrier electric field near the front surface, which is the light receiving surface, suppresses the recombination of photoelectrons and holes generated by the incident of light with a short blue wavelength, and the photoelectric near the light receiving surface. Conversion is possible. A concentration gradient type barrier electric field region is formed on both the upper and lower sides (both left and right in FIG. 1) sandwiching the boundary surface jk3 between the P + region 2 and the P region 3 on the front side.

The P + region 6 on the back side is for generating a concentration gradient type barrier electric field generated by the concentration gradient of P + P in order to suppress the recombination of photoelectrons near the surface on the back side. A concentration gradient type barrier electric field region is formed on both the upper and lower sides (both left and right in FIG. 1) sandwiching the boundary surface jk4. The donor density, acceptor density, and depth thickness of the P + region 2, P region 3, N region 4, P region 5, and P + region 6 are the PN junction type barrier electric field generated in the depletion layer of the PN junction and the P + P. The concentration gradient type barrier electric field generated by the concentration gradient is set so as to be almost integrated in the depth direction to form one almost complete barrier electric field region Wd (20 to 40 μm is the optimum width of Wd. See FIG. 3). There is. FIG. 2 shows a specific example of the impurity concentration profile along the aa'line and the impurity concentration profile along the bb' line of the photoelectric conversion semiconductor device 1.

The outer surface electrodes 9 and 10 provided in the P + regions 2 and 6 on the front side and the back side of the photoelectric conversion semiconductor device 1 are connected to the ground and fixed to the ground potential. On the other hand, an external capacitance 30 for charge storage is connected between the outer surface electrode 12 provided in the N + region 11 and the ground. Further, an external load 32 is connected to the external capacity 30 via a switch 31.
The external circuit of FIG. 1 is an example. Instead of providing an external capacitance outside the photoelectric conversion semiconductor device 1, a charge storage capacitance (not shown) is formed inside the photoelectric conversion semiconductor device 1 and the capacitance is formed inside the photoelectric conversion semiconductor device 1. Both electrodes of the capacitance may be connected between the outer surface electrode 12 provided in the N + region 11 and the ground.

The energy band in the depth direction of the P + PNPP + junction 7 is as shown in FIG. 3, the energy levels of photoelectrons are highest in the P + regions 2 and 6 on the front side and the back side, and the energy level near the center of the N region 4 is the lowest. The N + region 11 is one step lower than the vicinity of the center of the N region 4.
The photoelectrons (e−) and holes (h +) generated by the incident light passing through the SiO2 region 8 on the front side are the sum of the concentration gradient type barrier electric field region and the PN junction type barrier electric field region generated by the P + P concentration gradients on the front side and the back side. Since the photoelectrons are immediately separated by the electric field of the barrier electric field region Wd, the photoelectrons move to the center of the N region 4 having the lowest energy level, and the holes move to the P + regions 2 and 6 on the front side and the back side without recombination. If the photoelectrons remain accumulated near the center of the N region 4, the depletion layer of the N region 4 becomes narrow, and the photoelectrons and the holes are easily recombined. In this embodiment, since the photoelectrons move to the side of the N + region 11 having the lowest energy level provided near the center of the N region 4, the depletion layer of the N region 4 does not become narrow.
The holes that reach the P + regions 2 and 6 on the front side and the back side are combined with the electrons supplied from the outer surface electrodes 9 and 10 and disappear. When the switch 31 is open, the photoelectrons that have reached the N + region 11 are accumulated in the + electrode 30a of the N + region 11, the outer surface electrode 12, and the external capacitance 30. In the external circuit of FIG. 1, when the switch 31 is closed, the photoelectrons accumulated in the external capacity 30 flow to the external load 32, and the photoelectrons accumulated in the + pole 30a of the N + region 11, the outer surface electrode 12, and the external capacity 30 flow. Here is an example of being reset.

A concentration gradient type barrier electric field region generated by a P + P concentration gradient near the front and back surfaces by fixing the front surface of the P + region 2 on the front side of the photoelectric conversion semiconductor device 1 and the back surface of the P + region 6 on the back side to the ground potential. Since the potential of the entire barrier electric field region Wd including the PN junction type barrier electric field region generated in the PN junction empty layer is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 1, the barrier The electric field at any location in the electric field region Wd is not affected by the disturbance, and the photoelectrons accumulated in the N + region 11 do not return to the side of the N region 4, so that a stable photoelectric conversion operation can be maintained.
Further, by fixing the front surface of the P + region 2 on the front side and the back surface of the P + region 6 on the back side to the ground potential, the electric field near the very surface of the front side of the P + region 2 and the electric field near the back surface of the P + region 6 is generated. It becomes zero, and as a result, the electrons that absorb heat energy very close to the surface of the P + region 6 and rise to the conduction band are immediately recombined with the vacancies on the spot, resulting in a surface dark current for charge charge storage. The risk of discharging the external capacity 30 is reduced, and the conversion efficiency can be further improved.

According to this embodiment, both the front and back sides of the N region 4 are sandwiched between the P regions 3 and 5 in the depth direction from the front surface side to the back surface side, and the outside of both P regions 3 and 5 is P + for generating a barrier electric field. A P + PNPP + junction 7 sandwiched between regions 2 and 6 is provided, of which the PNP junction is formed symmetrically in the front and back directions with the center in the depth direction of the N region 4 as the center, in the depth direction of the N region 4. By sucking out photoelectrons by the N + region 11 provided so as to be in contact with the central portion, the barrier electric field region Wd over almost the entire area of the P + PNPP + junction 7 can be easily formed, and the SiO2 region 8 on the surface side can be easily formed. Since the photoelectrons generated by the light incident through the light and the holes can be separated without recombination, and the photoelectrons can be sucked out from the vicinity of the center of the N region 4 to the N + region 11 whose energy level is one step lower, the photoelectrons can be generated in the N region 4. A photoelectric conversion semiconductor device 1 having high photoelectric conversion efficiency without staying can be obtained.
Further, when the P + regions 2 and 6 on the front and back surfaces of the photoelectric conversion semiconductor device 1 are fixed to the ground potential, they are generated in the density gradient type barrier electric field region generated by the P + P concentration gradients near the front and back surfaces and the PN junction. Since the potential of the entire barrier electric field region Wd including the PN junction type barrier electric field region is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 1, the electric field at any place in the barrier electric field region Wd. However, stable photoelectric conversion operation can be maintained without being affected by disturbance or returning the photoelectrons accumulated in the N + region 11 to the side of the N region 4.
Further, by fixing the front surface of the P + region 2 and the back surface of the P + region 6 to the ground potential, the electric fields near the front surface of the P + region 2 and near the back surface of the P + region 6 become zero, and as a result, the P + region becomes zero. Electrons that absorb heat energy very close to the surfaces of 2 and 6 and rise to the conduction band are immediately recombined with the pores on the spot, which may cause a surface dark current and discharge the external or internal capacitance. Is reduced, and the conversion efficiency can be further improved.

The photoelectric conversion semiconductor device according to the second embodiment of the present invention will be described with reference to FIG.
In FIG. 4, 50 is a photoelectric conversion semiconductor device that receives sunlight and generates photovoltaic power, the upper side is the front side, the lower side is the back side, and the depth direction is from top to bottom. An N region 51 having a substantially rectangular cross section is provided inside the photoelectric conversion semiconductor device 50. Protruding portions 51a and 51b projecting in the back side direction are formed near the left and right ends on the back side of the N region 51. Among the N regions 51, the P region 52 is provided so as to surround the periphery while contacting the back side surface, the upper surface, and the side peripheral surface excluding the back side end faces 51c and 51d of the back side protruding portions 51a and 51b. Near the left and right ends on the back side of the P region 52, stepped portions 52a and 52b are formed so as to surround the side surfaces of the protruding portions 51a and 51b. A PN junction surface is formed at the boundary between the N region 51 and the P region 52, and a PN junction type barrier electric field region is formed on both the upper and lower sides or the left and right sides of the PN junction surface.

On the outside of the front side of the P region 52, a front side P + region 53 extending in the surface direction so as to come into contact with the surface of the P region 52 is provided. The P + region 53 on the front side suppresses the recombination of photoelectrons near the front surface of the photoelectric conversion semiconductor device 50, so that a concentration gradient type barrier electric field generated by the concentration gradient of P + P is generated and photoelectric conversion to blue short wavelength light is performed. This is an area provided to improve efficiency. A concentration gradient type barrier electric field region is formed on both the upper and lower sides of the boundary surface between the P + region 53 and the P region 52.

Inside the back outside of the P region 52, P + regions 54, 55, 56 are provided along the surface direction so as to be in contact with the back surface of the P region 52 excluding the back end surfaces 52c and 52d of the step portions 52a and 52b. There is. The P + regions 54, 55, and 56 are regions provided to generate a concentration gradient type barrier electric field generated by the concentration gradient of P + P in order to suppress the recombination of photoelectrons near the back surface of the photoelectric conversion semiconductor device 50. .. Concentration gradient type barrier electric field regions are formed on both the upper and lower sides of the boundary surface between the P + regions 54, 55, 56 and the P region 52.
N + regions 57 and 58 for sucking photoelectrons are provided so as to come into contact with a part of the left and right ends on the back side of the N region 51. Specifically, N + regions 57 and 58 are provided in the projecting portions 51a and 51b in an embedded state. The photoelectron energy level of the N + regions 57 and 58 is one step lower than that of the N region 51, and has a function of sucking out the photoelectrons collected in the N region 51. The P + regions 54, 55, 56, the back end surfaces 52c, 52d of the stepped portions 52a, 52b, the back end surfaces 51c, 51d of the protruding portions 51a, 51b, and the back end surfaces 57a, 58a of the N + regions 57, 58 are parallel to the light receiving main surface. Form a flat surface. The photoelectric conversion layer 59 is composed of N regions 51, P regions 52, P + regions 53, 54, 55, 56, and N + regions 57, 58.

On the front side of the photoelectric conversion layer 59, an insulating SiO2 region 60 as a transparent light receiving window region is provided so as to be in contact with the surface of the P + region 53 except for the left and right ends on the front side. On the left and right sides of the SiO2 region 60, outer surface electrodes 61 and 62 having the first polarity conducting with the left and right ends of the front surface of the P + region 53 on the front side are provided.
On the back side of the photoelectric conversion layer 59, the outer surface electrode 63 having the first polarity conducting with the surface of the P + region 56, and the back of the P + regions 54 and 55 at the left and right ends are on the back outside except for the left and right ends of the P + region 56. External electrodes 64, 65 having the first polarity conducting with the surface of the P + regions 54, 55 are provided on the outside. Further, on the back outside of the N + regions 57 and 58, outer surface electrodes 66 and 67 having a second polarity conducting with the surface of the N + regions 57 and 58 are provided. Insulating SiO2 regions 68 and 69 are provided on the left and right side surfaces of the photoelectric conversion layer 59. Insulating SiO2 regions 70, 71, 72, 73 are provided on the outer surface other than the outer surface electrodes 63, 64, 65, 66, 67 on the back side of the photoelectric conversion layer 59.

The photoelectric conversion semiconductor device 50 passes through the center of the N region 51 in the left-right direction and is viewed from the symmetry line C1 extending in the depth direction. Regions 57, 58, outer surface electrodes 61, 62, 63, 64, 65, 66, 67, SiO2 regions 60, 68, 69, 70, 71, 72, 73 are formed symmetrically in the left-right line. Each outer surface electrode 61, 62, 63, 64, 65, 66, 67 is made of metal. The outer surface electrode 63 reflects the visible light component of the incident light that has reached the back side of the photoelectric conversion semiconductor device 50 and converts it again by photoelectric conversion or reflects the far infrared component of the incident light, so that the front and outer surfaces of the photoelectric conversion semiconductor device 50 are reflected. It has a function of suppressing the temperature rise of the photoelectric conversion semiconductor device 50 by emitting light from the semiconductor device 50.

Among the photoelectric conversion semiconductor devices 50, the outer surface electrodes 61, 62, 63, 64, 65 are connected to the ground and are fixed to the ground potential. On the other hand, an external capacitance 30 for charge storage is connected between the outer surface electrodes 66 and 67 and the ground. Further, an external load 32 is connected to the external capacity 30 via a switch 31. A capacitance (not shown) for accumulating charge is formed inside the photoelectric conversion semiconductor device 50, and both poles of this capacitance are connected between the outer surface electrodes 66 and 67 provided in the N + regions 57 and 58 and the ground. You can do it.

The energy levels of photoelectrons are highest in the front and back P + regions 53, 54, 55, and 56, and decrease in the order of the internal P regions 52, N region 51, and N + regions 57 and 58.
The photoelectrons (e−) and holes (h +) generated by the incident light passing through the SiO2 region 60 on the front side are the concentration gradient type barrier electric field generated by the P + P concentration gradients on the front side and the back side and the PN generated in the depletion layer of the PN junction. Since they are immediately separated by the junctional barrier electric field, the photoelectrons move to the N + regions 57 and 58 with the lowest energy levels and the holes move to the P + regions 53, 54, 55 and 56 without recombination.
The holes that reach the P + regions 53, 54, 55, and 56 are combined with the electrons supplied from the outer surface electrodes 61, 62, 63, 64, and 65 and disappear. When the switch 31 is open, the photoelectrons that have reached the N + regions 57 and 58 are accumulated in the + pole 30a of the N + regions 57 and 58, the outer surface electrodes 66 and 67, and the external capacitance 30. In the external circuit of FIG. 4, when the switch 31 is closed, the photoelectrons accumulated in the external capacitance 30 flow to the external load 32 and move to the N + regions 57, 58, the outer surface electrodes 66, 67, and the + pole 30a of the external capacitance 30. An example in which the accumulated photoelectrons are reset is shown.

By fixing the surfaces of the P + region 53 on the front side and the P + regions 54, 55, 56 on the back side of the photoelectric conversion semiconductor device 50 to the ground potential, the concentration gradient type barrier electric field region generated by the P + P concentration gradient near the front and back surfaces. Since the potential of the entire PN junction type barrier electric field region generated in the PN junction void layer is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 50, any location in the barrier electric field region The electric field is not affected by the disturbance, and the photoelectrons accumulated in the N + regions 57 and 58 do not return to the side of the N region 51, so that a stable photoelectric conversion operation can be maintained.
Further, by fixing the surface of the P + region 53, 54, 55, 56 to the ground potential, the electric field near the very surface on the front side of the P + region 53 and near the very surface on the back side of the 54, 55, 56 becomes zero. As a result, the electrons that have absorbed heat energy very close to the surface of the P + regions 53, 54, 55, and 56 and have risen to the conduction band are immediately recombined with the pores on the spot, resulting in a surface dark current and an electric charge. The risk of discharging the external capacity 30 for storage is reduced, and the conversion efficiency can be further improved.

According to this second embodiment, the P region 52 surrounds the N region 51 to form a multi-layered PN junction surface in the depth direction, and P + for preventing recombination is further formed on both the front and back surfaces of the P region 52. By providing regions 53, 54, 55, 56 and N + regions 57, 58 near the left and right ends of the back surface of the N region 51 to suck out photoelectrons, a barrier electric field is provided over almost the entire depth direction. A region can be formed, and the photoelectrons generated by light incident through the SiO2 region 60 and the holes are separated without recombination, and the photoelectrons are sucked from the N region 51 to the N + regions 57 and 58, which are one step lower in energy level. Therefore, photoelectrons do not stay in the N region 51, and a photoelectric conversion semiconductor device 50 having high photoelectric conversion efficiency can be obtained.
Further, the incident light that has reached the back surface side is reflected again in the surface direction by the outer surface electrode 63, and the visible light component is converted into photoelectrons, which also improves the conversion efficiency. Since the far-infrared component of the incident light is reflected by the outer surface electrode 63 and emitted to the outside from the surface of the photoelectric conversion semiconductor device 50, the installation base side of the photoelectric conversion semiconductor device 50 does not need to be heated, which imposes a burden on the cooling equipment. It can be reduced or the conversion efficiency can be prevented from deteriorating.
By fixing the surfaces of the P + regions 53, 54, 55, 56 of the photoelectric conversion semiconductor device 50 to the ground potential, the concentration gradient type barrier electric field region and the PN junction type barrier electric field generated by the P + P concentration gradient near the front and back surfaces. Since the potential in the entire region is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 50, the electric field at any location in the barrier electric field region is affected by the disturbance, or the N + regions 57 and 58. The photoelectrons accumulated in the N region 51 do not return to the side of the N region 51, and a stable photoelectric conversion operation can be maintained.
Further, by fixing the surface of the P + region 53, 54, 55, 56 to the ground potential, the electric field near the very surface on the front side of the P + region 53 and near the very surface on the back side of the 54, 55, 56 becomes zero. As a result, the electrons that have absorbed heat energy very close to the surface of the P + regions 53, 54, 55, and 56 and have risen to the conduction band are immediately recombined with the pores on the spot, resulting in a surface dark current and an electric charge. The risk of discharging the external capacity 30 for storage is reduced, and the conversion efficiency can be further improved.

The photoelectric conversion semiconductor device according to the third embodiment of the present invention will be described with reference to FIG.
In FIG. 5, reference numeral 70 denotes a photoelectric conversion semiconductor device that receives sunlight and generates photovoltaic power, the upper side is the front side, the lower side is the back side, and the depth direction is from top to bottom. Inside the photoelectric conversion semiconductor device 70, an N region 71 having a substantially T-shaped cross section is provided. A protruding portion 71a projecting in the back side direction is formed in the central portion on the back side of the N region 71. Among the N regions 71, the P region 72 is provided so as to surround the periphery while contacting the back side surface, the front side surface, and the side peripheral surface excluding the back side end surface of the back side protruding portion 71a. Near the center of the back side of the P region 72, a stepped portion 72a projecting on the front side of the projecting portion 71a is formed so as to surround the side surface of the projecting portion 71a. A PN junction surface is formed at the boundary between the N region 71 and the P region 72, and a PN junction type barrier electric field region is formed on both the upper and lower sides or the left and right sides of the PN junction surface.

On the outside of the front side of the P region 72, a front side P + region 73 extending in the surface direction so as to come into contact with the surface of the P region 72 is provided. The P + region 73 on the front side suppresses the recombination of photoelectrons near the front surface of the photoelectric conversion semiconductor device 70, so that a concentration gradient type barrier electric field generated by the concentration gradient of P + P is generated and photoelectric conversion to blue short wavelength light is performed. This is an area provided to improve efficiency. A concentration gradient type barrier electric field region is formed on both the upper and lower sides of the boundary surface between the P + region 73 and the P region 72.

Inside the back outside of the P region 72, the P + regions 74 and 75 are provided along the surface direction so as to come into contact with the back surface of the P region 72 excluding the back end surface 72b of the step portion 72a. The P + regions 74 and 75 are regions provided to generate a concentration gradient type barrier electric field generated by the concentration gradient of P + P in order to suppress the recombination of photoelectrons near the back surface of the photoelectric conversion semiconductor device 70. A concentration gradient type barrier electric field region is formed on both the upper and lower sides of the boundary surface between the P + regions 74 and 75 and the P region 72.
The N + region 76 for sucking out photoelectrons is provided so as to come into contact with the central portion on the back side of the N region 71. Specifically, the N + region 76 is provided in the projecting portion 71a in an embedded state. The photoelectron energy level of the N + region 76 is one step lower than that of the N region 71, and has a function of sucking out the photoelectrons collected in the N region 71. The P + regions 74 and 75, the back side end surface 72b of the step portion 72a, the back side end surface 71b of the projecting portion 71a, and the back side end surface 76a of the N + region 76 form a plane parallel to the light receiving main surface. The photoelectric conversion layer 77 is composed of the N region 71, the P region 72, the P + region 73, 74, 75, and the N + region 76.

On the front side of the photoelectric conversion layer 77, an insulating SiO2 region 78 as a transparent light receiving window region is provided so as to be in contact with the surface of the P + region 73 excluding the left and right ends on the front side. On the left and right sides of the SiO2 region 78, outer surface electrodes 79 and 80 having the first polarity that are conductive with the left and right ends of the front surface of the P + region 73 on the front side are provided.
On the back side of the photoelectric conversion layer 77, on the back outside excluding the left and right ends of the P + region 74, the outer surface electrode 81 having the first polarity conducting with the surface of the P + region 74, and the back outside excluding the left and right ends of the P + region 75. Is provided with an outer surface electrode 82 having a first polarity that is conductive with the surface of the P + region 75. Further, on the back outer side of the N + region 76, an outer surface electrode 83 having a second polarity conducting with the surface of the N + region 76 is provided. Insulating SiO2 regions 84 and 85 are provided on the left and right side surfaces of the photoelectric conversion layer 77. Insulating SiO2 regions 86, 87 are provided on the outer surface other than the outer surface electrodes 81, 82, 83 on the back side of the photoelectric conversion layer 77.

The photoelectric conversion semiconductor device 70 passes through the center of the N region 71 in the left-right direction, and when viewed from the symmetry line C2 extending in the depth direction, the N region 71, the P region 72, the P + region 73, 74, 75, and the N + region 76. , External electrodes 79, 80, 81, 82, 83, SiO2 regions 78, 84, 85, 86, 87 are formed symmetrically in the left-right line. Each outer surface electrode 79, 80, 81, 82, 83 is made of metal. The outer surface electrodes 81 and 82 reflect the visible light component of the incident light that has reached the back side of the photoelectric conversion semiconductor device 70, and perform photoelectric conversion again or reflect the far-infrared component of the incident light to reflect the far-infrared component of the incident light of the photoelectric conversion semiconductor device 70. It has a function of suppressing the temperature rise of the photoelectric conversion semiconductor device 70 by discharging it to the outside.

Among the photoelectric conversion semiconductor devices 70, the outer surface electrodes 79, 80, 81, 82 are connected to the ground and are fixed to the ground potential. On the other hand, an external capacitance 30 for charge storage is connected between the outer surface electrode 83 and the ground. Further, an external load 32 is connected to the external capacity 30 via a switch 31. A capacitance (not shown) for accumulating charge may be formed inside the photoelectric conversion semiconductor device 70, and both poles of this capacitance may be connected between the outer surface electrode 83 provided in the N + region 76 and the ground. ..

The energy levels of photoelectrons are highest in the front and back P + regions 73, 74, and 75, and decrease in the order of the internal P regions 72, N regions 71, and the back N + regions 76.
The photoelectrons (e−) and holes (h +) generated by the incident light passing through the SiO2 region 78 on the front side are the concentration gradient type barrier electric field generated by the P + P concentration gradients on the front side and the back side and the PN generated in the depletion layer of the PN junction. Since they are immediately separated by the junctional barrier electric field, the photoelectrons move to the N + region 76, which has the lowest energy level, and the holes move to the P + regions 73, 74, 75 without recombination.
The holes that reach the P + regions 73, 74, and 75 are combined with the electrons supplied by the outer surface electrodes 79, 80, 81, and 82 and disappear. When the switch 31 is open, the photoelectrons that have reached the N + region 76 are accumulated in the + pole 30a of the N + region 76, the outer surface electrode 83, and the external capacitance 30. In the external circuit of FIG. 5, when the switch 31 is closed, the photoelectrons accumulated in the external capacitance 30 flow to the external load 32, and the optoelectronics accumulated in the + pole 30a of the N + region 76, the outer surface electrode 83, and the external capacitance 30. Here is an example where is reset.

By fixing the surfaces of the P + region 73 on the front side and the P + regions 74 and 75 on the back side of the photoelectric conversion semiconductor device 70 to the ground potential, the concentration gradient type barrier electric field region and PN generated by the P + P concentration gradient near the front and back surfaces. Since the potential of the entire PN junction type barrier electric field region generated in the poor layer of the junction is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 70, the electric field at any place in the barrier electric field region can be applied. A stable photoelectric conversion operation can be maintained without being affected by disturbance or returning the photoelectrons accumulated in the N + region 76 to the side of the N region 71.
Further, by fixing the surfaces of the P + regions 73, 74, and 75 to the ground potential, the electric fields near the very surface on the front side of the P + region 73 and near the very surface on the back side of the 74, 75 become zero, and as a result, P +. Electrons that absorb heat energy very close to the surfaces of regions 73, 74, and 75 and rise to the conduction band immediately recombine with the pores on the spot, resulting in a surface dark current and an external capacity 30 for charge charge storage. The risk of discharging the electric charge is reduced, and the conversion efficiency can be further improved.

According to this third embodiment, the P region 72 surrounds the N region 71 to form a multi-layered PN junction surface in the depth direction, and P + for preventing recombination is further formed on both the front and back surfaces of the P region 72. By providing the regions 73, 74, and 75 and by providing the N + region 76 in the central portion on the back side of the N region 71 so as to suck out the photoelectrons, the barrier electric field region can be formed over almost the entire depth direction. , Photoelectrons generated by light incident through the SiO2 region 78 and holes can be separated without recombination, and the photoelectrons can be sucked from the N region 71 to the N + region 76, which is one step lower in energy level. A photoelectric conversion semiconductor device 70 having high photoelectric conversion efficiency without retention of photoelectrons can be obtained.
Further, the incident light that reaches the back surface side is reflected again in the surface direction by the outer surface electrodes 81 and 82, and the visible light component is converted into photoelectrons, which also improves the conversion efficiency. Since the far-infrared component of the incident light is reflected by the outer surface electrodes 81 and 82 and emitted to the outside from the surface of the photoelectric conversion semiconductor device 70, the installation base side of the photoelectric conversion semiconductor device 70 does not need to be heated, and the cooling equipment It is possible to reduce the burden and prevent deterioration of conversion efficiency.
By fixing the surfaces of the P + regions 73, 74, 75 of the photoelectric conversion semiconductor device 70 to the ground potential, the concentration gradient type barrier electric field region and the PN junction type barrier electric field region generated by the P + P concentration gradient near the front and back surfaces Since the potential over the entire range is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 70, the electric field at any location in the barrier electric field region is affected by the disturbance, or the photoelectrons accumulated in the N + region 76. Can maintain a stable photoelectric conversion operation without returning to the side of the N region 71.
Further, by fixing the surfaces of the P + regions 73, 74, and 75 to the ground potential, the electric fields near the very surface on the front side of the P + region 73 and near the very surface on the back side of the 74, 75 become zero, and as a result, P +. Electrons that absorb heat energy very close to the surfaces of regions 73, 74, and 75 and rise to the conduction band immediately recombine with the pores on the spot, resulting in a surface dark current and an external capacity 30 for charge charge storage. The risk of discharging the electric charge is reduced, and the conversion efficiency can be further improved.

The photoelectric conversion semiconductor device according to the fourth embodiment of the present invention will be described with reference to FIG.
In FIG. 6, 90 is a photoelectric conversion semiconductor device that receives sunlight and generates photovoltaic power, the upper side is the front side, the lower side is the back side, and the depth direction is from top to bottom. The photoelectric conversion semiconductor device 90 is provided with an N region 91 having a comb-shaped cross section (horizontally H-shaped). Among the N regions 91, the P region 92 is provided so as to surround the periphery while contacting the upper surface excluding the back surface and the side peripheral surface. A PN junction surface is formed at the boundary between the N region 91 and the P region 92, and a PN junction type barrier electric field region is formed on both the upper and lower sides and the left and right sides of the PN junction surface.

On the outside of the front side of the P region 92, a front side P + region 93 extending in the surface direction so as to come into contact with the surface of the P region 92 is provided. The P + region 93 on the front side suppresses the recombination of photoelectrons near the front surface of the photoelectric conversion semiconductor device 90, so that a concentration gradient type barrier electric field generated by the concentration gradient of P + P is generated and photoelectric conversion to blue short wavelength light is performed. This is an area provided to improve efficiency. A concentration gradient type barrier electric field region is formed on both the upper and lower sides of the boundary surface between the P + region 93 and the P region 92.
An N + region 94 for sucking out photoelectrons is provided so as to be in contact with the back surface of the N region 91 and the back surface of the P region 92 and extended along the surface direction. The central portion in the left-right direction of the N + region 94 is a protruding portion 94a that protrudes so as to be embedded in the central portion on the back side of the N region 91. The photoelectron energy level in the N + region 94 is one step lower than that in the N region 91, and has a function of sucking out the photoelectrons collected in the N region 91. The photoelectric conversion layer 95 is composed of the N region 91, the P region 92, the P + region 93, and the N + region 94.

On the front side of the photoelectric conversion layer 95, an insulating SiO2 region 96 as a transparent light receiving window region is provided so as to be in contact with the surface of the P + region 93 except for the left and right ends on the front side. On the left and right sides of the SiO2 region 96, outer surface electrodes 97 and 98 having the first polarity conducting with the left and right ends of the front surface of the front P + region 93 are provided.
Insulating SiO2 regions 99 and 100 are provided on the back side of the photoelectric conversion layer 95 except for the central portion of the N + region 94, and the N + region at the central portion is provided on the back outer side of the SiO2 regions 99 and 100. An outer surface electrode 101 having a second polarity conducting with the back outer surface of 94 is provided.

The photoelectric conversion semiconductor device 90 passes through the center of the N region 91 in the left-right direction, and when viewed from the symmetry line C3 extending in the depth direction, the N region 91, the P region 92, the P + region 93, the N + region 94, and the outer surface electrode 97. , 98, 101, SiO2 regions 96, 99, 100 are formed symmetrically in the left-right line. Each outer surface electrode 97, 98, 101 is made of metal. The outer surface electrode 101 reflects the visible light component of the incident light that has reached the back side of the photoelectric conversion semiconductor device 90, and performs photoelectric conversion again or reflects the far infrared component of the incident light, so that the front and outer surfaces of the photoelectric conversion semiconductor device 90 are reflected. It has a function of suppressing the temperature rise of the photoelectric conversion semiconductor device 90.

In the photoelectric conversion semiconductor device 90, the outer surface electrodes 97 and 98 are connected to the ground and fixed to the ground potential. On the other hand, an external capacitance 30 for charge storage is connected between the outer surface electrode 101 and the ground. Further, an external load 32 is connected to the external capacity 30 via a switch 31. A charge storage capacitance (not shown) may be formed inside the photoelectric conversion semiconductor device 90, and both electrodes of this capacitance may be connected between the outer surface electrode 101 provided in the N + region 94 and the ground. ..

The energy level of photoelectrons is highest in the P + region 93 on the front side, and decreases in the order of the P region 92, the N region 91, and the N + region 94.
The photoelectrons (e−) and holes (h +) generated by the incident light passing through the SiO2 region 96 on the front side are the concentration gradient type barrier electric field generated by the P + P concentration gradient on the front side and the PN junction type barrier generated in the depletion layer of the PN junction. Since the photoelectrons are immediately separated by the electric field, the photoelectrons move to the N + region 94 having the lowest energy level and the holes move to the P + region 93 without recombination.
The holes that reach the P + region 93 are combined with the electrons supplied from the outer surface electrodes 97 and 98 and disappear. When the switch 31 is open, the photoelectrons that have reached the N + region 94 are accumulated in the + electrode 30a of the N + region 94, the outer surface electrode 101, and the external capacitance 30. In the external circuit of FIG. 6, when the switch 31 is closed, the photoelectrons accumulated in the external capacitance 30 flow to the external load 32, and the optoelectronics accumulated in the + pole 30a of the N + region 94, the outer surface electrode 101, and the external capacitance 30. Here is an example where is reset.

When the surface of the P + region 93 on the front side of the photoelectric conversion semiconductor device 90 is fixed to the ground potential, the PN generated in the PN junction between the concentration gradient type barrier electric field region generated by the P + P concentration gradient near the front and back surfaces and the PN junction. Since the potential over the entire junction type barrier electric field region is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 90, the electric field at any location in the barrier electric field region is affected by the disturbance, or N +. The photoelectrons accumulated in the region 94 do not return to the side of the N region 91, and a stable photoelectric conversion operation can be maintained.
Further, since the surface of the P + region 93 is fixed to the ground potential, the electric field near the very surface on the front side of the P + region 93 becomes zero, and as a result, heat energy is absorbed near the very surface of the P + region 93 and the conduction band is absorbed. Since the electrons that have risen to the surface are immediately recombined with the vacancies on the spot, there is less risk that the external capacitance 30 for charge storage will be discharged as a surface dark current, and the conversion efficiency will be further improved. Can be done.

According to this fourth embodiment, the N region 91 having a comb-shaped cross section is surrounded by the P region 92 to form a multi-layered PN junction surface in the depth direction, and further, P + for preventing recombination is formed on the front surface of the P region 92. By providing the region 93 and providing the N + region 94 on the back surface of the N region 91 to suck out photoelectrons, a barrier electric field region can be formed over almost the entire depth direction, and the SiO2 region 96 on the front side can be formed. Since the photoelectrons generated by the light incident through the light and the holes can be separated without recombination, and the photoelectrons can be sucked from the N region 91 to the N + region 94, which is one step lower in the energy level, the photoelectrons stay in the N region 91. Instead, a photoelectric conversion semiconductor device 90 having high photoelectric conversion efficiency can be obtained.
Further, the incident light that has reached the back surface side is reflected again in the surface direction by the outer surface electrode 101, and the visible light component is converted into photoelectrons, which also improves the conversion efficiency. Since the far-infrared component of the incident light is reflected by the outer surface electrode 101 and emitted to the outside from the surface of the photoelectric conversion semiconductor device 90, the installation base side of the photoelectric conversion semiconductor device 90 does not need to be heated, which imposes a burden on the cooling equipment. It can be reduced or the conversion efficiency can be prevented from deteriorating.
Further, when the surface of the P + region 93 on the front side of the photoelectric conversion semiconductor device 90 is fixed to the ground potential, it is generated in the empty layer of the PN junction with the concentration gradient type barrier electric field region generated by the P + P concentration gradient near the front and back surfaces. Since the potential over the entire PN junction type barrier electric field region is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 90, the electric field at any location in the barrier electric field region is affected by the disturbance. The photoelectrons accumulated in the N + region 94 do not return to the side of the N region 91, and a stable photoelectric conversion operation can be maintained.
Further, by fixing the surface of the P + region 93 to the ground potential, the electric field near the very surface on the front side of the P + region 93 becomes zero, and as a result, heat energy is absorbed near the very surface of the P + region 93 and the conduction band is absorbed. Since the electrons that have risen to the surface are immediately recombined with the vacancies on the spot, there is less risk that the external capacitance 30 for charge charge storage will be discharged as a surface dark current, and the conversion efficiency will be further improved. Can be done.

The photoelectric conversion semiconductor device according to the fifth embodiment of the present invention will be described with reference to FIGS. 7 and 8.
In FIG. 7, 110 is a photoelectric conversion semiconductor device that receives sunlight and generates photovoltaic power, the upper side is the front side, the lower side is the back side, and the depth direction is from top to bottom. The photoelectric conversion semiconductor device 110 is provided with an N region 111 having a comb-shaped cross section inside. A projecting portion 111a projecting in the back side direction is formed in the central portion on the back side of the N region 111. Among the N regions 111, the P region 112 is provided so as to surround the periphery while contacting the back side surface, the front side surface, and the side peripheral surface excluding the back side end surface 111b of the back side protruding portion 111a. In the central portion on the back side of the P region 112, a stepped portion 112a is formed so as to surround the side surface of the protruding portion 111a so as to project on the back side one step. A PN junction surface is formed at the boundary between the N region 111 and the P region 112, and a PN junction type barrier electric field region is formed on both the upper and lower sides or the left and right sides of the PN junction surface.

On the outside of the front side of the P region 112, a front side P + region 113 extending in the surface direction so as to come into contact with the surface of the P region 112 is provided. The P + region 113 on the front side suppresses the recombination of photoelectrons near the front surface of the photoelectric conversion semiconductor device 110, so that a concentration gradient type barrier electric field generated by the concentration gradient of P + P is generated and photoelectric conversion for blue short wavelength light is performed. This is an area provided to improve efficiency. Concentration gradient type barrier electric field regions are formed on both the upper and lower sides of the boundary surface between the P + region 113 and the P region 112.

Within the back outer side of the P region 112, the P + regions 114 and 115 are provided along the surface direction so as to come into contact with the back side surface of the P region 112 excluding the back side end surface 112b of the step portion 112a. The P + regions 114 and 115 are regions provided to generate a concentration gradient type barrier electric field generated by the concentration gradient of P + P in order to suppress the recombination of photoelectrons near the back surface of the photoelectric conversion semiconductor device 110. Concentration gradient type barrier electric field regions are formed on both the upper and lower sides of the boundary surface between the P + regions 114 and 115 and the P region 112.
The N + region 116 for sucking out photoelectrons is provided so as to come into contact with the central portion on the back side of the N region 111. Specifically, the N + region 116 is provided in the projecting portion 111a in an embedded state. The photoelectron energy level of the N + region 116 is one step lower than that of the N region 111, and has a function of sucking out the photoelectrons collected in the N region 111. The P + regions 114 and 115, the back side end surface 112b of the step portion 112a, the back side end surface 111b of the projecting portion 111a, and the back side end surface 116a of the N + region 116 form a plane parallel to the light receiving main surface. The photoelectric conversion layer 117 is composed of the N region 111, the P region 112, the P + region 113, 114, 115, and the N + region 116.

On the front side of the photoelectric conversion layer 117, an insulating SiO2 region 118 as a transparent light receiving window region is provided so as to be in contact with the surface of the P + region 113 excluding the left and right ends on the front side. On the left and right sides of the SiO2 region 118, outer surface electrodes 119 and 120 having the first polarity conducting with the left and right ends of the front surface of the P + region 113 on the front side are provided.
On the back side of the photoelectric conversion layer 117, on the back outside excluding the left and right ends of the P + region 114, the outer surface electrode 121 having the first polarity conducting with the surface of the P + region 114, and the back outside excluding the left and right ends of the P + region 115. Is provided with an outer surface electrode 122 having a first polarity that is conductive with the surface of the P + region 115. Further, on the back outer side of the N + region 116, an outer surface electrode 123 having a second polarity conducting with the surface of the N + region 116 is provided. Insulating SiO2 regions 124 and 125 are provided on the left and right side surfaces of the photoelectric conversion layer 117. Insulating SiO2 regions 126, 127 are provided on the outer surface other than the outer surface electrodes 121, 122, and 123 on the back side of the photoelectric conversion layer 117.

The photoelectric conversion semiconductor device 110 passes through the center of the N region 111 in the left-right direction and is viewed from the symmetry line C4 extending in the depth direction, the N region 111, the P region 112, the P + region 113, 114, 115, and the N + region 116. , External electrodes 119, 120, 121, 122, 123, SiO2 regions 118, 124, 125, 126, 127 are formed symmetrically in the left-right line. Each outer surface electrode 119, 120, 121, 122, 123 is made of metal. The outer surface electrodes 121 and 122 reflect the visible light component of the incident light that has reached the back side of the photoelectric conversion semiconductor device 110, and perform photoelectric conversion again or reflect the far-infrared component of the incident light to reflect the far-infrared component of the incident light of the photoelectric conversion semiconductor device 110. It has a function of suppressing the temperature rise of the photoelectric conversion semiconductor device 110 by discharging it to the outside.

Among the photoelectric conversion semiconductor devices 110, the outer surface electrodes 119, 120, 121, 122 are connected to the ground and are fixed to the ground potential. On the other hand, an external capacitance 30 for charge storage is connected between the outer surface electrode 123 and the ground. Further, an external load 32 is connected to the external capacity 30 via a switch 31. A charge storage capacity (not shown) may be formed inside the photoelectric conversion semiconductor device 70, and both electrodes of this capacity may be connected between the outer surface electrode 123 provided in the N + region 116 and the ground. ..

The energy levels of photoelectrons are highest in the P + regions 113, 114, and 115 on the front and back sides, and decrease in the order of the internal P regions 112, N regions 111, and the back side N + regions 116.
The photoelectrons (e−) and holes (h +) generated by the incident light passing through the SiO2 region 118 on the front side are the concentration gradient type barrier electric field generated by the P + P concentration gradients on the front and back sides and the PN generated in the depletion layer of the PN junction. Since they are immediately separated by the junctional barrier electric field, the photoelectrons move to the N + region 116, which has the lowest energy level, and the holes move to the P + regions 113, 114, 115 without recombination.
The holes that reach the P + regions 113, 114, 115 combine with the electrons supplied by the outer surface electrodes 119, 120, 121, 122 and disappear. When the switch 31 is open, the photoelectrons that have reached the N + region 116 are accumulated in the + pole 30a of the N + region 116, the outer surface electrode 123, and the external capacitance 30. In the external circuit of FIG. 7, when the switch 31 is closed, the photoelectrons accumulated in the external capacitance 30 flow to the external load 32, and the optoelectronics accumulated in the + pole 30a of the N + region 116, the outer surface electrode 123, and the external capacitance 30. Here is an example where is reset.

By fixing the surfaces of the P + region 113 on the front side and the P + regions 114 and 115 on the back side of the photoelectric conversion semiconductor device 110 to the ground potential, the concentration gradient type barrier electric field region and PN generated by the P + P concentration gradient near the front and back surfaces. Since the potential of the entire PN junction type barrier electric field region generated in the poor layer of the junction is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 110, the electric field at any place in the barrier electric field region can be applied. A stable photoelectric conversion operation can be maintained without being affected by disturbance or returning the photoelectrons accumulated in the N + region 116 to the side of the N region 111.
Further, by fixing the surfaces of the P + regions 113, 114, 115 to the ground potential, the electric fields near the very surface on the front side of the P + region 113 and near the very surface on the back side of the 114, 115 become zero, and as a result, P +. Electrons that absorb heat energy very close to the surfaces of regions 113, 114, and 115 and rise to the conduction band immediately recombine with the pores on the spot, resulting in a surface dark current and an external capacity 30 for charge charge storage. The risk of discharging the electric charge is reduced, and the conversion efficiency can be further improved.

According to this fifth embodiment, the P region 112 surrounds the N region 111 to form a multi-layered PN junction surface in the depth direction, and P + for preventing recombination is further formed on both the front and back surfaces of the P region 112. By providing the regions 113, 114, and 115 and by providing the N + region 116 in the central portion on the back side of the N region 111 to suck out the photoelectrons, the barrier electric field region can be formed over almost the entire depth direction. , Photoelectrons generated by light incident through the SiO2 region 118 and holes can be separated without recombination, and the photoelectrons can be sucked from the N region 111 to the N + region 116, which is one step lower in energy level. A photoelectric conversion semiconductor device 110 having high photoelectric conversion efficiency without retention of photoelectrons can be obtained.
Further, the incident light that reaches the back surface side is reflected again in the surface direction by the outer surface electrodes 121 and 122, and the visible light component is converted into photoelectrons, which also improves the conversion efficiency. Since the far-infrared component of the incident light is reflected by the outer surface electrodes 121 and 122 and emitted to the outside from the surface of the photoelectric conversion semiconductor device 110, the installation base side of the photoelectric conversion semiconductor device 110 does not need to be heated, and the cooling equipment It is possible to reduce the burden and prevent deterioration of conversion efficiency.
By fixing the surfaces of the P + regions 113, 114, 115 of the photoelectric conversion semiconductor device 110 to the ground potential, the concentration gradient type barrier electric field region and the PN junction type barrier electric field region generated by the P + P concentration gradient near the front and back surfaces Since the potential over the entire range is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 110, the electric field at any location in the barrier electric field region is affected by the disturbance, or the photoelectrons accumulated in the N + region 116. Can maintain a stable photoelectric conversion operation without returning to the side of the N region 111.
Further, by fixing the surfaces of the P + regions 113, 114, 115 to the ground potential, the electric fields near the very surface on the front side of the P + region 113 and near the very surface on the back side of the 114, 115 become zero, and as a result, P +. Electrons that absorb heat energy very close to the surfaces of regions 113, 114, and 115 and rise to the conduction band immediately recombine with the pores on the spot, resulting in a surface dark current and an external capacity 30 for charge charge storage. The risk of discharging the electric charge is reduced, and the conversion efficiency can be further improved.

The photoelectric conversion semiconductor device according to the sixth embodiment of the present invention will be described with reference to FIG.
In FIG. 9, 130 is a photoelectric conversion semiconductor device that receives sunlight and generates photovoltaic power, the upper side is the front side, the lower side is the back side, and the depth direction is from top to bottom. The photoelectric conversion semiconductor device 130 has a photoelectric conversion layer (see reference numeral 145) described later inside.
The photoelectric conversion layer 131 is provided with an N region 140 having an inverted T-shaped cross section. A protruding portion 140a projecting in the front side is formed in the central portion on the front side of the N region 140. A P region 141 on the front side is provided on the front surface of the N region 140 excluding the front end surface 140b of the projecting portion 140a on the front side so as to be in contact with the surface of the N region 140, and the P region 141 on the front side is provided on the back side of the N region 140. , The P region 142 on the back side is provided so as to come into contact with the surface of the N region 140. In the P region 141 on the front side, a stepped portion 141a is formed so as to surround the side surface of the protruding portion 140a. A PN junction surface is formed at the boundary between the N region 140 and the P regions 141 and 142, and a PN junction type barrier electric field region is formed on both the upper and lower sides of the PN junction surface.

A P + region 143 is provided so as to surround the front side and the side surface side of the front side P region 141 excluding the front side end surface 141b of the step portion 141a, the side surface side of the N region 140, and the back side and the side surface side of the back side P region 142. There is. The projecting portion 140a of the N region 140 is provided with the N + region 144 in an embedded state so as to be in contact with the N region 140. The front side of the P + region 143, the step portion 141a, the projecting portion 140a, and the N + region 144 forms a plane parallel to the light receiving main surface. The photoelectric conversion layer 145 is composed of the N region 140, the P region 141, 142, the P + region 143, and the N + region 144. In the P + region 143, in order to suppress the recombination of photoelectrons near the front surface of the photoelectric conversion semiconductor device 130, a concentration gradient type barrier electric field generated by the concentration gradient of P + P is generated, and the photoelectric conversion efficiency for blue short wavelength light is increased. This is an area provided for improvement. A concentration gradient type barrier electric field region is formed on both the upper and lower sides of the boundary surface between the P + region 143 and the P regions 141 and 142.

An insulating SiO2 region 146 as a transparent light receiving window region is provided so as to be in contact with the front surface of the photoelectric conversion layer 145. Near the left and right ends of the SiO2 region 146, outer surface electrodes 147 and 148 having the first polarity conducting with the left and right ends of the front surface of the P + region 143 are provided, and N + is embedded in the center of the SiO2 region 146. A second polarity outer surface electrode 149 that comes into contact with the front surface of the region 144 is provided. A second N region 150 is provided so as to surround the back side and the side surface side of the photoelectric conversion layer 145, and a second N + region 151 is further provided on the back side of the second N region 150. A metal reflection region 152 is provided on the back side of the second N + region 151.

The photoelectric conversion semiconductor device 130 passes through the center of the N region 140 in the left-right direction, and when viewed from the symmetry line C5 extending in the depth direction, the N region 140, the P region 141, 142, the P + region 143, the N + region 144, and the outer surface. An example is shown in which the electrodes 147, 148, 149, SiO2 region 146, the second N region 150, the second N + region 151, and the metal reflection region 152 are left-right axisymmetric. Each outer surface electrode 147, 148, 149 is made of metal. The metal reflection region 152 reflects the visible light component of the incident light that has reached the back side of the photoelectric conversion semiconductor device 130, performs photoelectric conversion again, or reflects the far-infrared component of the incident light, and the photoelectric conversion semiconductor device 130. It has a function of suppressing the temperature rise of the photoelectric conversion semiconductor device 130 by discharging it to the outside of the surface of the above.

In the photoelectric conversion semiconductor device 130, the outer surface electrodes 147 and 148 and the metal reflection region 152 are connected to the ground and are fixed to the ground potential. On the other hand, an external capacitance 30 for charge storage is connected between the outer surface electrode 149 and the ground. Further, an external load 32 is connected to the external capacity 30 via a switch 31. A charge storage capacity (not shown) may be formed inside the photoelectric conversion semiconductor device 130, and both electrodes of this capacity may be connected between the outer surface electrode 149 provided in the N + region 144 and the ground. ..

The energy level of photoelectrons in the photoelectric conversion layer 145 is highest in the P + region 143, and decreases in the order of P regions 141, 142, N region 140, and N + region 144.
The photoelectrons (e−) and holes (h +) generated by the incident light passing through the SiO2 region 146 on the front side are the concentration gradient type barrier electric field generated by the P + P concentration gradients on the front and back sides and the PN generated in the depletion layer of the PN junction. Since they are immediately separated by the junctional barrier electric field, the photoelectrons move to the N + region 144, which has the lowest energy level, and the holes move to the P + region 143, without recombination.
The holes that reach the P + region 143 are combined with the electrons supplied from the outer surface electrodes 147 and 148 and disappear. When the switch 31 is open, the photoelectrons that have reached the N + region 144 are accumulated in the N + region 144, the outer surface electrode 149, and the + pole 30a of the external capacitor 30. In the external circuit of FIG. 9, when the switch 31 is closed, the photoelectrons stored in the external capacity 30 flow to the external load 32, and the photoelectrons stored in the N + region 144, the outer surface electrode 149, and the + pole 30a of the external capacity 30 are stored. Here is an example where is reset.

When the front surface of the P + region 143 of the photoelectric conversion semiconductor device 130 is fixed to the ground potential, the concentration gradient type barrier electric field region generated by the P + P concentration gradient near the front and back surfaces and the PN junction generated in the PN junction empty layer. Since the potential in the entire range of the type barrier electric field region is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 130, the electric field at any place in the barrier electric field region is affected by the disturbance, or the N + region. The photoelectrons accumulated in 144 do not return to the side of the N region 140, and a stable photoelectric conversion operation can be maintained.
Further, by fixing the surface of the P + region 143 to the ground potential, the electric field near the very surface on the front side of the P + region 143 becomes zero, and as a result, heat energy is absorbed near the very surface of the P + region 143 to absorb the conduction band. Since the electrons that have risen to the surface are immediately recombined with the vacancies on the spot, there is less risk that the external capacitance 30 for charge charge storage will be discharged as a surface dark current, and the conversion efficiency will be further improved. Can be done.

According to the sixth embodiment, the N region 140 is provided in the photoelectric conversion unit 145 provided inside the photoelectric conversion semiconductor device 130, and the P regions 141 and 142 are provided on the front side and the back side of the N region 140 excluding the front center portion. The P + region 143 is provided so as to surround the front side and the side surface side of the step portion 141a of the front side P region 141 except for the front end surface 141b, the side surface side of the N region 140, and the back side and the side surface side of the back side P region 142. By providing an N + region 144 in the center of the front side of the N region 140 to suck out photoelectrons, a depletion layer is formed over almost the entire depth direction, and photoelectrons and holes generated by light incident through the SiO2 region 146 are formed. The photoelectrons can be sucked from the N region 140 to the N + region 144, which has a lower energy level, so that the photoelectrons do not stay in the N region 140 and the photoelectric conversion semiconductor device 130 has high photoelectric conversion efficiency. Is obtained.
Further, the incident light that reaches the back surface side is reflected again in the surface direction by the metal reflection region 152, and the visible light component is converted into photoelectrons, which also improves the conversion efficiency. Since the far-infrared component of the incident light is reflected by the metal reflection region 152 and emitted to the outside from the surface of the photoelectric conversion semiconductor device 130, the installation base side of the photoelectric conversion semiconductor device 130 does not need to be heated, and the cooling equipment It is possible to reduce the burden and prevent deterioration of conversion efficiency.
Further, when the front surface of the P + region 143 of the photoelectric conversion semiconductor device 130 is fixed to the ground potential, the PN generated in the PN junction between the concentration gradient type barrier electric field region generated by the P + P concentration gradient near the front and back surfaces and the PN junction. Since the potential over the entire junction type barrier electric field region is fixed, even if a disturbance such as a surge occurs around the photoelectric conversion semiconductor device 130, the electric field at any location in the barrier electric field region is affected by the disturbance, or N +. The photoelectrons accumulated in the region 144 do not return to the side of the N region 140, and a stable photoelectric conversion operation can be maintained.
Further, since the surface of the P + region 143 is fixed to the ground potential, the electric field near the very surface on the front side of the P + region 143 becomes zero, and as a result, heat energy is absorbed near the very surface on the front side of the P + region 143. Since the electrons that have risen in the conduction band are immediately recombined with the vacancies on the spot, there is less risk of becoming a surface dark current and discharging the external capacity 30 for charge storage, further improving conversion efficiency. Can be planned.

The photoelectric conversion semiconductor device according to the seventh embodiment of the present invention will be described with reference to FIG.
In FIG. 10, 160 is a photoelectric conversion semiconductor device that receives sunlight and generates photovoltaic power, the upper side is the front side, the lower side is the back side, and the depth direction is from top to bottom. The photoelectric conversion semiconductor device 160 has a configuration in which photoelectric conversion units 161, 162, and 163 having the same configuration as the photoelectric conversion semiconductor device 130 of FIG. 9 are integrally provided in the left-right direction. The structure and function of each photoelectric conversion unit 161, 162, 163 are the same as those of the photoelectric conversion semiconductor device 130 of FIG.

The outer surface electrodes 147 and 148 of the photoelectric conversion unit 161 are connected to the ground, and the outer surface electrode 149 is connected to the + pole 331a of the first external capacitance 331 for charge storage. The outer surface electrodes 147 and 148 of the photoelectric conversion unit 162 are connected to the + pole 331a of the external capacitance 331, and the outer surface electrode 149 is connected to the + pole 332a of the second external capacitance 332 for charge storage. The outer surface electrodes 147 and 148 of the photoelectric conversion unit 163 are connected to the + pole 332a of the external capacitance 332, and the outer surface electrode 149 is connected to the + pole 332a of the third external capacitance 333 for charge storage. An external load 32 is connected to the third external capacity 333 via a switch 31.

According to the photoelectric conversion semiconductor device 160 configured as shown in FIG. 10, it is possible to apply a voltage three times the photovoltaic voltage per photoelectric conversion unit 161, 162, 163 to the external load 32.

The present invention is applicable to a photoelectric conversion semiconductor device for a solar cell that incidents sunlight and converts it into electrical energy.

1 Photoelectric conversion semiconductor device 2 Front side P + region 3 Front side P region 4 N region 5 Back side P region 6 Back side P + region 9, 10, 12 External electrode 11 N + region 30 External capacitance

Conventionally, as one of the measures for improving the conversion efficiency, as shown in JP-A-07-297444, for example , a method of forming a plurality of PN junction surfaces parallel to the surface of a photoelectric conversion semiconductor device in the depth direction (vertical direction). Was proposed.
However, in the photoelectric conversion semiconductor device of JP-A No. 07-297444 described above, photoelectrons move to a place having a low energy level in the N region and stay there, but in the N region depending on the amount of the staying photoelectrons. The potential fluctuates without being fixed, and the stagnant photoelectrons narrow the depletion layer in the N region to promote the recoupling of photoelectrons and vacancies, and recoupling is likely to occur near the surface of the photoelectric conversion semiconductor device, resulting in conversion efficiency. There was a limit to the improvement.

In the invention according to claim 1,
A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
Inside the photoelectric conversion semiconductor device, both the front and back sides of the N region are sandwiched between the front side P region and the back side P region in the depth direction from the front side to the back side, and the front side and the back side of the back side P region of the front side P region are further sandwiched. ,
A P + PNPP + junction sandwiched between the P + region on the front side and the P + region on the back side for generating a concentration gradient type barrier electric field generated by the concentration gradient of P + P is provided.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided at the center of the N region in the depth direction so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided outside the N + region.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
It is characterized by.
In the invention according to claim 2,
A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
An N region is provided in the photoelectric conversion semiconductor device, and
A P region is provided so as to surround the front side, the back side, and the side surface side except for a part near the left and right ends on the back side of the N region.
On the front side of the P region, a P + region on the front side is provided so as to be in contact with the surface of the P region.
On the back side of the P region, a P + region on the back side is provided so as to be in contact with the surface of the P region.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided near the left and right ends on the back side of the N region so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided on the back side of the N + region.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
It is characterized by.
In the invention according to claim 3,
A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
A P region is provided so as to surround the front side, the back side, and the side surface side excluding the back side central portion of the N region provided in the photoelectric conversion semiconductor device.
On the front side of the P region, a P + region on the front side is provided so as to be in contact with the surface of the P region.
On the back side of the P region, a P + region on the back side is provided so as to be in contact with the surface of the P region.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided in the central portion on the back side of the N region so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided on the back side of the N + region.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
It is characterized by.
In the invention according to claim 4,
It is a photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the surface side.
A P region is provided so as to surround the front side and the side surface side excluding the back side of the N region having a comb-shaped cross section provided in the photoelectric conversion semiconductor device.
A P + region is provided on the front side of the P region so as to be in contact with the surface of the P region.
On the front side of the P + region, an outer surface electrode having a first polarity conducting with the light receiving window region and the surface of the P + region is provided.
An N + region for sucking photoelectrons is provided on the back side of the N region so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided on the back side of the N + region.
Connect the outer electrode of the first polarity to the ground, and between the outer electrode of the second polarity and the ground,
Connecting the charge storage capacity provided inside or outside the photoelectric conversion semiconductor device,
It is characterized by.
In the invention according to claim 5,
A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
A P region is provided so as to surround the front side, the back side, and the side surface side excluding the back side central portion of the N region having a comb-shaped cross section provided in the photoelectric conversion semiconductor device.
On the front side of the P region, a P + region on the front side is provided so as to be in contact with the surface of the P region.
On the back side of the P region, a P + region on the back side is provided so as to be in contact with the surface of the P region.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided in the central portion on the back side of the N region so as to be in contact with the N region.
On the back side of the N + region, an outer surface electrode having a second polarity conducting with the N + region is provided.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
It is characterized by.
In the invention according to claim 6,
A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
A photoelectric conversion layer is provided in the photoelectric conversion semiconductor device, and the photoelectric conversion layer is provided.
This photoelectric conversion layer is
The N region provided in the photoelectric conversion semiconductor device and
On the front side excluding the central part of the front side of the N region, a P region on the front side provided in contact with the surface of the N region and a P region on the front side.
A P region on the back side provided on the back side of the N region so as to be in contact with the surface of the N region, and a P region on the back side.
All or part of the front side of the P region on the front side and the side surface side, the side surface side of the N region, and the P + region provided so as to surround the back side and the side surface side of the P region on the back side.
An N + region on the front side provided in contact with the N region at the center of the front side of the N region,
Including
On the front side of the photoelectric conversion layer , a light receiving window region, an outer surface electrode having a first polarity conducting with the surface of the P + region, and an outer surface electrode having a second polarity conducting with the N + region are provided.
A metal reflection region is provided on the back side of the P + region via at least one of the second N region and the second N + region.
The outer electrode of the first polarity and the metal reflection region are connected to the ground, and a charge storage capacity provided inside or outside the photoelectric conversion semiconductor device is provided between the outer electrode of the second polarity and the ground. Having connected,
It is characterized by.
In each claim, the N + region may be provided so as to be embedded in the N region.

Claims (6)

A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
Inside the photoelectric conversion semiconductor device, both the front and back sides of the N region are sandwiched between the front side P region and the back side P region in the depth direction from the front side to the back side, and the front side and the back side of the back side P region of the front side P region are further sandwiched. , A P + PNPP + junction sandwiched between the P + region on the front side and the P + region on the back side for generating a concentration gradient type barrier electric field generated by the concentration gradient of P + P is provided.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided at the center of the N region in the depth direction so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided outside the N + region.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
A photoelectric conversion semiconductor device characterized by. A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
An N region is provided in the photoelectric conversion semiconductor device, and
A P region is provided so as to surround the front side, the back side, and the side surface side except for a part near the left and right ends on the back side of the N region.
On the front side of the P region, a P + region on the front side is provided so as to be in contact with the surface of the P region.
On the back side of the P region, a P + region on the back side is provided so as to be in contact with the surface of the P region.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided near the left and right ends on the back side of the N region so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided on the back side of the N + region.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
A photoelectric conversion semiconductor device characterized by. A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
A P region is provided so as to surround the front side, the back side, and the side surface side excluding the back side central portion of the N region provided in the photoelectric conversion semiconductor device.
On the front side of the P region, a P + region on the front side is provided so as to be in contact with the surface of the P region.
On the back side of the P region, a P + region on the back side is provided so as to be in contact with the surface of the P region.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided in the central portion on the back side of the N region so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided on the back side of the N + region.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
A photoelectric conversion semiconductor device characterized by. It is a photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the surface side.
A P region is provided so as to surround the front side and the side surface side excluding the back side of the N region having a comb-shaped cross section provided in the photoelectric conversion semiconductor device.
A P + region is provided on the front side of the P region so as to be in contact with the surface of the P region.
On the front side of the P + region, an outer surface electrode having a first polarity conducting with the light receiving window region and the surface of the P + region is provided.
An N + region for sucking photoelectrons is provided on the back side of the N region so as to be in contact with the N region.
An outer surface electrode having a second polarity conducting with the N + region is provided on the back side of the N + region.
The outer electrode of the first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
A photoelectric conversion semiconductor device characterized by. A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
A P region is provided so as to surround the front side, the back side, and the side surface side excluding the back side central portion of the N region having a comb-shaped cross section provided in the photoelectric conversion semiconductor device.
On the front side of the P region, a P + region on the front side is provided so as to be in contact with the surface of the P region.
On the back side of the P region, a P + region on the back side is provided so as to be in contact with the surface of the P region.
On the front side of the P + region on the front side, an outer surface electrode having a first polarity conducting with the surface of the light receiving window region and the P + region on the front side is provided.
On the back side of the P + region on the back side, an outer surface electrode having a first polarity conducting with the surface of the P + region on the back side is provided.
An N + region for sucking photoelectrons is provided in the central portion on the back side of the N region so as to be in contact with the N region.
On the back side of the N + region, an outer surface electrode having a second polarity conducting with the N + region is provided.
The outer electrode of each first polarity was connected to the ground, and the charge storage capacitance provided inside or outside the photoelectric conversion semiconductor device was connected between the outer electrode of the second polarity and the ground.
A photoelectric conversion semiconductor device characterized by. A photoelectric conversion semiconductor device that photoelectrically converts sunlight incident from the front side.
A photoelectric conversion layer is provided in the photoelectric conversion semiconductor device, and the photoelectric conversion layer is provided.
This photoelectric conversion layer is
The N region provided in the photoelectric conversion semiconductor device and
On the front side excluding the central part of the front side of the N region, a P region on the front side provided in contact with the surface of the N region and a P region on the front side.
A P region on the back side provided on the back side of the N region so as to be in contact with the surface of the N region, and a P region on the back side.
All or part of the front side of the P region on the front side and the side surface side, the side surface side of the N region, and the P + region provided so as to surround the back side and the side surface side of the P region on the back side.
An N + region on the front side provided in contact with the N region at the center of the front side of the N region,
Including
On the front side of the photoelectric conversion unit, a light receiving window region, an outer surface electrode having a first polarity conducting with the surface of the P + region, and an outer surface electrode having a second polarity conducting with the N + region are provided.
A metal reflection region is provided on the back side of the P + region via at least one of the second N region and the second N + region.
The outer electrode of the first polarity and the metal reflection region are connected to the ground, and a charge storage capacity provided inside or outside the photoelectric conversion semiconductor device is provided between the outer electrode of the second polarity and the ground. Having connected,
A photoelectric conversion semiconductor device characterized by.

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