JP6463937B2 - Photoelectric conversion element and method for manufacturing photoelectric conversion element - Google Patents

Description

  The present invention relates to a photoelectric conversion element capable of obtaining a high S / N ratio.

Conventionally, a photoelectric conversion element using _{CuIn 1-x Ga x Se 1} -y S y is a chalcopyrite-type semiconductor in the p-type semiconductor layer is utilized primarily as a solar cell, high light absorption coefficient, high It has advantages such as quantum efficiency and energy conversion efficiency, and little deterioration due to light irradiation (for example, see Non-Patent Documents 1 and 2).

  On the other hand, a photoelectric conversion device that reduces dark current by devising a film structure has been devised (for example, Patent Document 1). Like this photoelectric conversion device, there are few examples in which a chalcopyrite semiconductor is operated by applying an electric field for the purpose of an image sensor or the like, and cadmium sulfide (CdS), which is the mainstream in solar cells, is used as an n-type semiconductor layer. (For example, patent document 1).

Jpn.J.Appl.Phys.vol.32, Suppl.32-3, pp.113-115 (1993) Tokyo University of Agriculture and Technology Doctoral Dissertation "Application of ternary compound semiconductors to optical devices" Katsushi Tanaka, 1996

JP 2007-123720 A

  However, in the photoelectric conversion element using the chalcopyrite type semiconductor described in Non-Patent Documents 1 and 2 as the photoelectric conversion layer, when an electric field application operation is performed as in an image sensor, for example, the dark current increases. As a result, sufficient S / N characteristics could not be obtained.

  Further, the photoelectric conversion device described in Patent Document 1 is not preferable in that cadmium is used for the n-type semiconductor layer. Moreover, since the band gap of cadmium sulfide is 2.4 eV, it absorbs blue light and is not preferable as a visible light image sensor.

  In addition, when a wide gap n-type semiconductor is applied to the n-type semiconductor layer to reduce dark current, it is difficult to obtain a good pn junction if the uniformity of the wide gap n-type semiconductor is insufficient. Thus, when the reverse bias voltage is applied, if the voltage increases, the dark current may not be suppressed.

  Accordingly, an object of the present invention is to provide a visible light photoelectric conversion element capable of obtaining a good pn junction, reducing dark current, and obtaining a high S / N ratio, and a method for manufacturing the photoelectric conversion element. And

The photoelectric conversion element according to one aspect of the present invention includes a first electrode layer is laminated on the first electrode layer, and the p-type semiconductor layer Ru carrier concentration ¹⁰ 15 ^~10 17 ^{cm -3} der, the p type semiconductor are stacked in layers, the n-type semiconductor layer having a first resistance, laminated on the n-type semiconductor layer, the carrier concentration is at 10 ^{1 0} cm ^-3 or less, the first higher than the resistance second A n-type semiconductor layer comprising a non-doped gallium oxide layer having resistance and a second electrode layer stacked on the non-doped gallium oxide layer, wherein the n-type semiconductor layer has a carrier concentration increased by oxygen defect or impurity implantation in the structure, a depletion layer between the p-type semiconductor layer and the n-type semiconductor layer is Ru Hiroga the p-type semiconductor layer side.

  A characteristic that a dark current can be reduced, a good pn junction can be obtained, a dark current can be reduced, and a photoelectric conversion element for visible light capable of obtaining a high S / N ratio, and a method for manufacturing the photoelectric conversion element can be provided. An effect is obtained.

It is a figure which shows the cross section of the photoelectric conversion element 10 of embodiment. It is a figure which shows the dark current-voltage characteristic of the photoelectric conversion element 10 of embodiment. It is a figure which shows the photocurrent (dark current) -voltage characteristic at the time of the reverse bias of the photoelectric conversion element 10 of embodiment. It is a figure which shows the irradiation light wavelength dependence of the quantum efficiency of the photoelectric conversion element 10 of embodiment. It is a figure which shows the difference in the dark current characteristic by the presence or absence of the alteration of the surface of the p-type semiconductor layer.

  Hereinafter, an embodiment to which the photoelectric conversion element of the present invention and the method for manufacturing the photoelectric conversion element are applied will be described.

  FIG. 1 is a diagram illustrating a cross section of a photoelectric conversion element 10 according to an embodiment.

  The photoelectric conversion element 10 of the embodiment includes a substrate 1, an electrode 2, a p-type semiconductor layer 3, an n-type semiconductor layer 4, a non-doped gallium oxide layer 5, and an electrode 6.

In the embodiment, a chalcopyrite semiconductor is used for the p-type semiconductor layer 3, gallium oxide (Ga ₂ O ₃ ), which is a wide gap n-type semiconductor, is used for the n-type semiconductor layer 4 of the photoelectric conversion element, and oxygen defects An object of the present invention is to provide a photoelectric conversion element 10 that reduces the dark current and increases the sensitivity to visible light by increasing the carrier concentration of gallium oxide with a dopant element.

  As the substrate 1, for example, a glass substrate can be used. The photoelectric conversion element 10 may receive light from either the upper side or the lower side in FIG. For example, when light is incident from above, the electrode 6 is required to be a translucent electrode, but the substrate 1 may not be transparent. In this case, for example, a silicon substrate or the like may be used as the substrate 1.

  When light is incident from the lower side, the substrate 1 and the electrode 2 are required to be a light-transmitting substrate and electrode, but the electrode 6 may not be transparent. In addition, you may be comprised so that all the board | substrate 1, electrode 2, and electrode 6 may have translucency.

  As the electrode 2, for example, gold or a thin film electrode such as molybdenum, tungsten, or tantalum can be used. The electrode 2 is used as a negative electrode. The electrode 2 is an example of a first electrode layer.

  For example, a gold thin film may be formed on the surface of the substrate 1 by an evaporation method, and a molybdenum, tungsten, or tantalum thin film may be formed on the surface of the substrate 1 by a sputtering method or the like. When it is desired to provide a light-transmitting property to a gold thin film, molybdenum, tungsten, or tantalum thin film, the film thickness may be thin enough to ensure the light-transmitting property. Further, as the electrode 2, an ITO (Indium Tin Oxide) film formed by vapor deposition or the like may be used. In addition, since the electrode 2 should just be comprised with the electrically conductive film, it is not limited to the thing of the material described here.

p-type semiconductor layer 3 is composed of chalcopyrite semiconductor _{(e.g., CuIn 1-x Ga x Se} 1-y S y , etc.). _{Here, CuIn 1-x Ga x Se} 1-y S x in _y is 0~1 (0 ≦ x ≦ 1) , y is 0~1 (0 ≦ y ≦ 1) .

  The p-type semiconductor layer 3 made of chalcopyrite semiconductor can be formed on the electrode 2 by, for example, multi-source deposition, MBE (three-stage method), sputtering, etc., and the film thickness is, for example, 0.5 μm. About 3 μm.

  A DC voltage is applied between the electrode 2 and the electrode 6 to the p-type semiconductor layer 3. The DC voltage can be applied by connecting a DC power source between the electrode 2 and the electrode 6 in a direction in which the electrode 2 is a negative electrode and the electrode 6 is a positive electrode.

The n-type semiconductor layer 4 is a layer that blocks (suppresses) injection of holes from the electrode 6 to the p-type semiconductor layer 3 and is composed of a gallium oxide (Ga ₂ O ₃ ) layer. The chalcopyrite semiconductor layer used as the p-type semiconductor layer 3 has a carrier concentration of 10 ¹⁵ to 10 ¹⁷ / cm ⁻³ , which is higher than that of gallium oxide. Therefore, in Embodiment 1, the oxide used as the n-type semiconductor layer 4 is used. The carrier concentration of the gallium (Ga ₂ O ₃ ) film is increased. As an example, the band gap of the gallium oxide (Ga ₂ O ₃ ) film used as the n-type semiconductor layer 4 is about 4.9 eV.

Thus, the gallium oxide (Ga ₂ O ₃ ) layer having a high carrier concentration can be formed on the p-type semiconductor layer 3 by, for example, a pulse laser deposition method. The film thickness of the n-type semiconductor layer 4 is, for example, about 0.01 μm to 1 μm. The reason why the gallium oxide (Ga ₂ O ₃ ) layer having a high carrier concentration is formed by the pulsed laser deposition method is that the binding energy is high and it is difficult to form by the vacuum deposition method or the sputtering method.

When the n-type semiconductor layer 4 is formed by pulse laser deposition (PLD), Ga ₂ O ₃ containing 0% to 10% of SnO ₂ is used as a target material. In addition, the frequency of the pulse laser used in the pulse laser vapor deposition method is desirably 1 Hz or less, for example. By using a laser having a low pulse frequency such as 1 Hz or less, the transmittance and uniformity of a tin-doped gallium oxide (tin-doped Ga ₂ O ₃ ) film formed as the n-type semiconductor layer 4 is improved. The quantum efficiency of the photoelectric conversion element can be improved.

Further, the substrate temperature during the deposition of the n-type semiconductor layer 4 is preferably from room temperature to 800 ° C., and the oxygen partial pressure is set to 0 Pa to 1 Pa. By using Ga ₂ O ₃ containing 0% to 10% of SnO ₂ as a target material, Sn can be implanted into the gallium oxide (Ga ₂ O ₃ ) layer used as the n-type semiconductor layer 4.

  Further, the impurity is not limited to Sn, and for example, at least one element of Ge, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, or W may be used. Any of these elements may be used together with Sn.

In order to increase the carrier concentration of the gallium oxide (Ga 2 _{O 3)} layer is used as the n-type semiconductor layer 4, instead of injecting the impurities, gallium oxide containing oxygen defects (Ga 2 _{O 3)} layer formed May be.

As described above, the carrier concentration of the gallium oxide (Ga ₂ O ₃ ) layer used as the n-type semiconductor layer 4 is increased because of the balance with the carrier concentration of the chalcopyrite semiconductor layer used as the p-type semiconductor layer 3. This is because the depletion layer is shifted to the chalcopyrite type semiconductor layer side by taking.

The carrier concentration of the gallium oxide (Ga ₂ O ₃ ) layer whose carrier concentration is not increased by impurity implantation or oxygen defect is about 10 ¹⁰ cm ⁻³ or less, whereas the carrier concentration of the chalcopyrite semiconductor layer is 10 ^Since it is about ¹⁵ to 10 ¹⁷ cm ⁻³ , there is a large difference in carrier concentration.

In such a state, even if the gallium oxide (Ga ₂ O ₃ ) layer (n layer) whose carrier concentration is not increased and the chalcopyrite semiconductor layer (p layer) are joined, the depletion layer is not gallium oxide ( It is mainly formed inside the (Ga ₂ O ₃ ) layer (n layer).

In the embodiment, the carrier concentration of the gallium oxide (Ga ₂ O ₃ ) layer used as the n-type semiconductor layer 4 is increased in order to expand the depletion layer to the chalcopyrite semiconductor layer and shift the spectral sensitivity to the visible light side. ing.

  When stacking the n-type semiconductor layer 4 on the p-type semiconductor layer 3, it is preferable not to expose the surface of the p-type semiconductor layer 3 to the atmosphere. By forming the n-type semiconductor layer 4 without exposing the surface of the p-type semiconductor layer 3 to the atmosphere, alteration of the surface of the p-type semiconductor layer 3 can be suppressed, and the dark current is reduced as compared with the case where it is exposed to the atmosphere. it can. The effect of suppressing alteration without exposing the surface of the p-type semiconductor layer 3 to the atmosphere will be described later with reference to FIG.

The non-doped gallium oxide layer 5 is stacked on the n-type semiconductor layer 4. The non-doped gallium oxide layer 5 may be formed by, for example, a sputtering method, a pulse laser deposition method, or the like, and may be formed of non-doped gallium oxide (Ga ₂ O ₃ ) with a thickness of 50 to 400 nm. The non-doped gallium oxide layer 5 has a much lower conductivity than the n-type semiconductor layer 4 (gallium oxide (Ga ₂ O ₃ ) layer whose carrier concentration is not increased by impurity implantation or oxygen defects), and therefore is an insulator rather than a semiconductor. Close to. Therefore, the non-doped gallium oxide layer 5 can be handled as a so-called semi-insulating layer having semi-insulating properties.

The substrate temperature during the formation of the non-doped gallium oxide layer 5 is desirably set in the range of room temperature to 400 ° C., and the oxygen partial pressure is set in the range of 0 Pa to 1 Pa. The film forming conditions for the non-doped gallium oxide layer 5 may be set as appropriate so that the specific resistance falls within a range of, for example, 10 ¹¹ Ωcm or more.

  The electrode 6 is made of, for example, an ITO film. The ITO film is formed on the non-doped gallium oxide layer 5 by vapor deposition or the like. The electrode 6 is used as a positive electrode. The electrode 6 is an example of a second electrode layer.

  As the electrode 6, another metal thin film such as a gold thin film may be used in the same manner as the electrode 2. Note that the electrode 2 is not necessarily required to have a high visible light transmittance and may be formed of a conductive material, and is not limited to the materials described here.

FIG. 2 is a diagram illustrating dark current-voltage characteristics of the photoelectric conversion element 10 according to the embodiment. The dark current (Dark) -voltage characteristics shown in FIG. 2 are as follows: a CuIn _0.48 Ga _0.52 S ₂ film as the p-type semiconductor layer 3, a Ga ₂ O ₃ film doped with tin as the n-type semiconductor layer 4, and a non-doped gallium oxide layer 5. This is a characteristic obtained by the photoelectric conversion element 10 including a non-doped Ga ₂ O ₃ film (semi-insulating layer).

The CuIn _0.48 Ga _0.52 S ₂ film (p-type semiconductor layer 3) was formed by sputtering, and the film thickness was 1 μm, and the film was formed without heating the substrate 1.

The substrate temperature by pulse laser deposition for forming tin-doped Ga ₂ O ₃ (n-type semiconductor layer 4) is 300 ° C., and the thickness of tin-doped Ga ₂ O ₃ (n-type semiconductor layer 4) is 50 nm. is there.

The non-doped Ga ₂ O ₃ film (non-doped gallium oxide layer 5) is formed by a pulse laser deposition method, the substrate temperature is room temperature, and the film thickness is 100 nm.

  The photoelectric conversion element 10 manufactured under such a manufacturing condition showed clear rectification characteristics as shown in FIG. From such characteristics, it can be confirmed that a good pn junction is obtained inside the photoelectric conversion element 10. For example, when a high resistance semi-insulating layer is not provided like the non-doped gallium oxide layer 5, if the film quality of the p-type semiconductor layer 3 is poor and pinholes or the like are generated, There is a possibility that the electrode 2 and the electrode 6 are partially conducted (via the very thin n-type semiconductor layer 4) and a good pn junction cannot be obtained.

  On the other hand, in the photoelectric conversion element 10 according to the embodiment, the non-doped gallium oxide layer 5 is provided between the stacked body of the p-type semiconductor layer 3 and the n-type semiconductor layer 4 and the electrode 6, whereby the p-type semiconductor is provided. Even if pinholes or the like exist in the layer 3 and conduction between the electrodes is caused by the pinholes or the like, the pinholes or the like can be covered with the non-doped gallium oxide layer 5 as a semi-insulating layer. Therefore, it is considered that a good pn junction can be obtained inside the photoelectric conversion element 10 and a clear rectification characteristic as shown in FIG. 2 is obtained.

  FIG. 3 is a diagram illustrating a photocurrent (dark current) -voltage characteristic at the time of reverse bias of the photoelectric conversion element 10 according to the embodiment. The voltage value on the horizontal axis in FIG. 3 indicates the voltage value of the reverse bias, and the direction of the reverse bias is a direction in which a positive voltage is applied to the electrode 2 with the electrode 6 as a reference. FIG. 3 also shows the photocurrent divided into three wavelength bands of blue, green, and red, dark current, and line types.

The photocurrent (dark current) -voltage characteristics shown in FIG. 3 are as follows: CuIn _0.48 Ga _0.52 S ₂ film as the p-type semiconductor layer 3, tin-doped Ga ₂ O ₃ film as the n-type semiconductor layer 4, non-doped gallium oxide layer 5 In the photoelectric conversion element 10 including a non-doped Ga ₂ O ₃ film (semi-insulating layer), photocurrent (dark current) -voltage characteristics obtained when a reverse bias is applied.

  It can be seen that the signal current increases rapidly from the time when the applied voltage as the reverse bias exceeds 3 V, and the avalanche multiplication phenomenon of the photogenerated charges has started. On the other hand, it can be seen that the dark current multiplication phenomenon requires an applied voltage rather than the signal current. Avalanche multiplication is a phenomenon caused by impact ionization of charge, but it is thought that the charge causing impact ionization is very small in the dark.

FIG. 4 is a diagram illustrating the irradiation light wavelength dependency of the quantum efficiency of the photoelectric conversion element 10 according to the embodiment. The dependence of the quantum efficiency on the irradiation light wavelength shown in FIG. 4 is as follows: CuIn _0.48 Ga _0.52 S ₂ film as p-type semiconductor layer 3, tin-doped Ga ₂ O ₃ film as n-type semiconductor layer 4, and non-doped Ga as non-doped gallium oxide layer 5. _This is a characteristic obtained in the photoelectric conversion element 10 including the ₂ O ₃ film (semi-insulating layer). FIG. 4 shows the irradiation light wavelength dependence of the quantum efficiency when the reverse bias is set to 0V, 1V, 2V, 3V, 3.5V, and 4V.

Here, since the CuIn _0.48 Ga _0.52 S ₂ film (CIGS film) as the p-type semiconductor layer 3 is formed by the sputtering method, there is a composition shift and a poor crystallinity. Although the efficiency is a low value of about 5%, it can be seen that at an applied voltage of 3.5 V, the quantum efficiency exceeds 100% in the entire visible light region due to the avalanche multiplication phenomenon of the photogenerated charges.

  Thus, in the photoelectric conversion element 10 of the embodiment, the avalanche multiplication phenomenon of the photogenerated charges can be caused at a low voltage of 10 V or less.

As described above, the photoelectric conversion element 10 of the embodiment uses a chalcopyrite semiconductor for the p-type semiconductor layer 3, and gallium oxide (Ga ₂ O ₃₎ that is a wide gap n-type semiconductor for the n-type semiconductor layer 4 of the photoelectric conversion element. ) To increase the carrier concentration of gallium oxide due to oxygen defects and dopant elements, and further, form a non-doped gallium oxide layer 5 between the stacked body of the p-type semiconductor layer 3 and the n-type semiconductor layer 4 and the electrode 6. It is realized by providing.

  By using such a photoelectric conversion element 10, it is possible to reduce dark current, have sensitivity to visible light, have a good pn junction, and obtain high quantum efficiency by avalanche multiplication.

  For example, when a semi-insulating layer such as the non-doped gallium oxide layer 5 is not provided, if the film quality of the p-type semiconductor layer 3 is poor and a pinhole or the like is generated, the electrode 2 and the electrode 6 are partially conducted. There is a risk that a good pn junction cannot be obtained.

  However, in the photoelectric conversion element 10 according to the embodiment, the non-doped gallium oxide layer 5 serving as a semi-insulating layer is provided between the electrode 6 and the stacked body of the p-type semiconductor layer 3 and the n-type semiconductor layer 4. As a result of forming a good pn junction inside the photoelectric conversion element 10, clear rectification characteristics and high quantum efficiency due to avalanche multiplication can be obtained. .

  Further, according to the embodiment, it is possible to provide the photoelectric conversion element 10 that can cause the avalanche multiplication phenomenon of photogenerated charges at a low voltage of 10 V or less and can be applied to a high sensitivity sensor.

Finally, the results of evaluating the suppression of alteration of the surface of the p-type semiconductor layer 3 will be described. FIG. 5 is a diagram showing a difference in dark current characteristics depending on whether or not the surface of the p-type semiconductor layer 3 is altered. Here, the non-doped Ga ₂ O ₃ layer 5 is directly formed on the p-type semiconductor layer 3 without forming the n-type semiconductor layer 4 between the p-type semiconductor layer 3 and the non-doped Ga ₂ O ₃ layer 5. The formed element was evaluated for suppression of alteration of the surface of the p-type semiconductor layer 3.

From the viewpoint of suppressing the alteration of the surface of the p-type semiconductor layer 3, even in an element in which the non-doped Ga ₂ O ₃ layer 5 is directly formed on the p-type semiconductor layer 3, the p-type semiconductor layer 3 and the non-doped Ga 2 _This is because an effect similar to that of the photoelectric conversion element 10 in which the n-type semiconductor layer 4 is formed between the ₂ O ₃ layer 5 can be obtained.

The dark current characteristic shown by the triangular plot in FIG. 5 is that a CuIn _0.5 Ga _0.5 Se ₂ film is formed as the p-type semiconductor layer 3 by the MBE method (three-stage method), and then a non-doped Ga ₂ O ₃ film (semi-insulating layer). Is a dark current-voltage characteristic obtained when a reverse bias is applied to an element formed by sputtering.

The dark current characteristics for comparison shown by the round plots are as follows. After the CuIn _0.5 Ga _0.5 Se ₂ film was formed by the MBE method (three-stage method), the surface of the CuIn _0.5 Ga _0.5 Se ₂ film was once exposed to the atmosphere. after allowed to, undoped Ga ₂ O ₃ layer 5 dark current (semi-insulating layer) obtained in the device was formed by sputtering - voltage characteristics.

The film forming conditions of the p-type semiconductor layer 3 and the non-doped Ga ₂ O ₃ layer 5 in both elements are as follows. In the MBE apparatus, the p-type semiconductor layer 3 was formed at the substrate temperature of 350 ° C. for 12 minutes at the substrate temperatures of 880 ° C., 1000 ° C., and 210 ° C. in the first stage film formation. In the second stage film formation, Cu and Se were formed at boat temperatures of 1150 ° C. and 210 ° C., respectively, and the substrate temperature was increased from 350 ° C. to 550 ° C. (temperature increase rate: 30 ° C./min) for 8 minutes. In the third stage, In, Ga, and Se were formed at boat temperatures of 860 ° C., 975 ° C., and 210 ° C., respectively, and the substrate temperature was 500 ° C. for 2 minutes. The film thickness of the p-type semiconductor layer 3 is 1 μm.

The non-doped Ga ₂ O ₃ layer 5 was formed in a sputtering apparatus under the conditions of a substrate temperature of 25 ° C., an RF output of 140 W, an oxygen introduction amount of 1 sccm, and an argon introduction amount of 13 sccm with a deposition time of 20 minutes and 45 seconds. The film thickness of the non-doped Ga ₂ O ₃ layer 5 is 100 nm.

As shown in FIG. 5, after depositing a CuIn _0.5 Ga _0.5 Se ₂ film (p-type semiconductor layer 3), the sample is transferred to another deposition chamber while maintaining the vacuum state without exposing the surface to the atmosphere. Then, by forming a gallium oxide layer (Ga ₂ O ₃ layer 5), alteration of the surface of the CuIn _0.5 Ga _0.5 Se ₂ film (p-type semiconductor layer 3) due to exposure to the atmosphere is suppressed, which is more than when exposed to the atmosphere. Even dark current can be reduced.

Therefore, similarly in the photoelectric conversion element 10 in which the n-type semiconductor layer 4 is formed between the p-type semiconductor layer 3 and the non-doped Ga ₂ O ₃ layer 5, the CuIn _0.5 Ga _0.5 Se ₂ film (p-type semiconductor layer 3 ), The sample is transferred to another film formation chamber while maintaining the vacuum state without exposing the surface to the atmosphere, and the n-type semiconductor layer 4 is formed. The film is transferred to a film forming chamber and a gallium oxide layer (Ga ₂ O ₃ layer 5) is formed, so that alteration of the surface of the CuIn _0.5 Ga _0.5 Se ₂ film (p-type semiconductor layer 3) due to atmospheric exposure is suppressed, The photoelectric conversion element 10 in which the dark current is reduced as compared with the case where it is exposed to the atmosphere can be manufactured.

Since the n-type semiconductor layer 4 uses gallium oxide (Ga ₂ O ₃ ), which is a wide gap n-type semiconductor, and the carrier concentration of gallium oxide is increased by oxygen defects and dopant elements, CuIn _0.5 Ga _0.5 Se ₂ After the film (p-type semiconductor layer 3) is formed, forming the n-type semiconductor layer 4 while keeping the vacuum state without exposing to the atmosphere is very effective for reducing the defect level. Note that without exposure to the atmosphere, the CuIn _0.5 Ga _0.5 Se ₂ film (p-type semiconductor layer 3) after film formation is moved to the next film formation chamber in an environment (under reduced pressure) that is depressurized from the atmosphere. That means.

  As mentioned above, although the photoelectric conversion element of the exemplary embodiment of the present invention and the manufacturing method of the photoelectric conversion element have been described, the present invention is not limited to the specifically disclosed embodiment, Various modifications and changes can be made without departing from the scope of the claims.

DESCRIPTION OF SYMBOLS 10 Photoelectric conversion element 1 Substrate 2 Electrode 3 P-type semiconductor layer 4 N-type semiconductor layer 5 Non-doped gallium oxide layer 6 Electrode

Claims (4)

A first electrode layer;
Laminated on the first electrode layer, and the p-type semiconductor layer Ru carrier concentration ¹⁰ 15 ^~10 17 ^{cm -3} der,
Laminated on the p-type semiconductor layer, and the n-type semiconductor layer having a first resistor,
Laminated on the n-type semiconductor layer, and the carrier concentration is 10 ^{1 0} cm ^-3 or less, and the gallium oxide layer of non-doped with the first of the second resistor is higher than the resistance,
A second electrode layer laminated on the non-doped gallium oxide layer,
The n-type semiconductor layer is composed of a gallium oxide layer whose carrier concentration is increased by oxygen defects or impurity implantation ,
The p-type depletion layer between the semiconductor layer and the n-type semiconductor layer that has spread into the p-type semiconductor layer side, the photoelectric conversion element. Gallium oxide layer carrier concentration is increased size by impurity implantation for forming the n-type semiconductor layer, Sn, Ge, Si, Ti , Zr, Hf, V, Nb, Ta, Cr, Mo, or of the W The photoelectric conversion element according to claim 1, wherein at least one element is implanted as an impurity.   The photoelectric conversion element according to claim 1, wherein the p-type semiconductor layer is formed of a semiconductor layer mainly composed of a chalcopyrite semiconductor. Forming a p-type semiconductor layer having a carrier concentration of 10 ¹⁵ to 10 ¹⁷ cm ⁻³ ;
After forming the p-type semiconductor layer, the p-type semiconductor layer without exposure to the atmosphere, on the p-type semiconductor layer, an oxygen defect or gallium oxide layer carrier concentration is increased size by impurity implantation Forming an n-type semiconductor layer that is configured and has a first resistance;
On the n-type semiconductor layer, the carrier concentration is at 10 ^{1 0} cm ^-3 or less, seen including a step of forming a gallium oxide layer of non-doped with a high second resistance than the first resistor ,
A method for manufacturing a photoelectric conversion element, wherein a depletion layer between the p-type semiconductor layer and the n-type semiconductor layer extends to the p-type semiconductor layer side .

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