JP3208219B2 - Photovoltaic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photovoltaic device,
In particular, for example, a transparent electrode, a semiconductor layer, a first back electrode, an insulating resin layer, and a second back electrode are stacked on a substrate for each cell, and the second back electrode is formed of a first back electrode and a semiconductor layer for each cell. Such a through-hole contact in which the second back electrode separated for each cell is connected to an adjacent first back electrode through an insulating resin layer at a connection portion, through a through hole formed in the substrate. (T
It relates to an HC (Through Hole Contact) type photovoltaic device.

[0002]

2. Description of the Related Art As shown in FIG. 6, a THC type photovoltaic device 1 has transparent electrodes 3 formed on a glass substrate 2 at predetermined intervals, and a semiconductor layer such as amorphous silicon is formed thereon. 4, the first back electrode 5, the insulating resin layer 6, and the second back electrode 7 are laminated, and the second back electrode 7 is connected to the transparent electrode 2 through the through hole 8 for each cell. 2 The back electrode 7 is the first electrode of the adjacent cell.
The second back surface electrode 7 is connected to the back surface electrode 5 and separated in the separation unit 10 for each cell.

When manufacturing such a THC type photovoltaic device 1, the transparent electrode 3, the semiconductor layer 4, and the first back electrode 5
Need to be separated for each cell.
The first back electrode 5 is also separated at the same inter-cell separation part as the transparent electrode 3.

[0004]

However, in the conventional structure in which the semiconductor layer 4 and the first back electrode 5 are separated from each other at the center of the patterning line of the transparent electrode 3 as described above,
The positioning of the inter-cell separation part was very difficult, and the workability was poor. Therefore, a main object of the present invention is to provide a photovoltaic device capable of improving the workability of separating a semiconductor layer and a first back electrode between cells.

[0005]

According to the present invention, there is provided a semiconductor device comprising:
A transparent electrode, a semiconductor layer, a first back electrode, an insulating resin layer, and a second back electrode are formed for each cell, and a second back electrode is formed for each cell through a through hole formed in the first back electrode and the semiconductor layer. A semiconductor layer and a first back surface in a photovoltaic device, wherein a second back surface electrode connected to a transparent electrode and separated for each cell is connected to a first back surface electrode of an adjacent cell at a connection portion through an insulating resin layer. A photovoltaic device, wherein an inter-cell separating portion for separating an electrode for each cell is disposed on a transparent electrode.

[0006]

For example, a transparent electrode is formed at intervals on a glass substrate, a semiconductor layer and a first back electrode are formed thereon, and the cells are separated on the transparent electrode by laser patterning using, for example, an Nd: YAG laser. I do.

[0007]

According to the present invention, since the semiconductor layer and the first back surface electrode are separated between the cells on the transparent electrode, the positioning becomes easier as compared with the case where these are patterned between the transparent electrodes. At the same time, since the transparent electrode has better heat conduction than the glass substrate, deformation at the edge of the inter-cell separation portion due to heat is reduced.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A THC photovoltaic device 1 (FIG. 5) according to an embodiment of the present invention is manufactured through the steps shown in FIGS. However, for simplicity of explanation, the second
The through-hole contact between the back electrode 9 and the transparent electrode 3 is omitted. As a first step, FIG.
As shown in FIG. 1, a transparent electrode 3 such as SnO ₂ or ITO is formed on a glass substrate 2 at a predetermined interval. Specifically, such a transparent electrode 3 is formed on the entire surface of the substrate 2 and then subjected to laser patterning (for example, with a Nd: YAG laser (wavelength = 1.06 μm, energy density 13 J / cm ² , pulse frequency 3 kHz)). Tens of μm
Width). The transparent electrode 3 has a thickness of 1000 to 6000 °.

As a subsequent second step, as shown in FIG. 2, over the entire surface of the glass substrate 2 on which the transparent electrode 3 has been formed, for example, by a known plasma CVD, a 5000-7000 ° thick amorphous silicon or the like is used. The semiconductor layer 4 has a thickness of, for example, 2000 to 500
A first back electrode 5 of, for example, ITO-Ag-Ti of 0 ° is formed.

In a subsequent third step, as shown in FIG. 3, in order to separate the semiconductor layer 4 and the first back electrode 5 in the inter-cell separation section 11, for example, a second harmonic of a laser beam of an Nd: YAG laser is used. Laser patterning. The wavelength of the YAG laser is, for example, 0.53 μm.
m, the energy density was 0.7 J / cm ² , and the pulse frequency was 4 kHz. In the third step, the inter-cell separation section 11 is arranged on the transparent electrode 3.
Therefore, much less strict patterning accuracy is not required as compared with the conventional case where the cells are separated at the intervals of the transparent electrodes 3. This is because the inter-cell separation part 11 has the transparent electrode 3
This is because it suffices if it is arranged on the upper side, and even if it is slightly shifted, it does not affect the characteristics. Further, in the conventional case, it was difficult to form a clean laser patterning edge due to the influence of heat. However, according to this embodiment, since the thermal conductivity of the transparent electrode 3 is larger than that of the glass substrate 2, it is unnecessary. Since the unnecessary laser energy propagates through the transparent electrode 3 and escapes, the edge finish in the inter-cell separation section 11 is good.

In the third step, even if the laser beam reaches the transparent electrode 3, the laser beam passes through the transparent electrode 3, so that the transparent electrode 3
It is not damaged by the laser. Then, FIG.
In the fourth step shown in FIG. 3, an insulating resin layer 6 having a thickness of, for example, 5000 to 5 .mu.m is formed on the entire surface of the glass substrate 2 from the state shown in FIG. At this time, the inner peripheral surface of the through hole 8 is insulated by the insulating resin layer 6. Then, the insulating resin layer in the connection portion 9 is removed at a predetermined position on the first back surface electrode 5 by, for example, laser patterning of XeCl excimer laser or photolithography technique. The wavelength of the XeCl excimer laser is a short wavelength of 308 nm. Therefore, the insulating resin layer 6 is processed and removed not by heat but by a chemical action by the energy of the photons. Therefore, the first back electrode 5 and the semiconductor layer 4 under the insulating resin layer 6 are not thermally damaged. In addition, the energy density of the XeCl excimer laser at this time is set to a value (for example, 0.3 J / cm ² or less) at which the insulating resin layer 6 can be removed but the first back electrode 5 is not processed. By irradiating a pulse number that can remove the thickness of the insulating resin layer 6, the connecting portion 9 can be accurately processed without causing any damage to the lower layer of the insulating resin layer 6.

In the next fifth step, as shown in FIG. 5, the film thickness of the same electrode material as that of the first back electrode 5 is, for example, from 2000 to 5 over the entire surface of the insulating resin layer 6.
After forming the second back electrode 7 of 000 °, the separation unit 10 separates the second back electrode 7 for each cell. By forming the second back surface electrode 7, the through hole (not shown) is connected to the transparent electrode 3 in the same cell as the through hole (not shown), and the connection portion 9 formed in the fourth step shown in FIG.
The second back electrode 7 and the first back electrode 5 of the adjacent cell are connected. Then, in the separation section 10, the second back electrode 7
Are separated for each cell, so that each cell is eventually connected in series in the horizontal direction.

In the fifth step, laser patterning using a XeCl excimer laser can be used. In this case, the wavelength was 308 nm, and the energy density was 0.3 J / cm ² or more. Since the insulating resin layer 6 is processed by the chemical action of the energy of the photons as described in the fourth step, the laser beam of the XeCl excimer laser reaches the insulating resin layer 6 in the separation unit 10. However, the insulating resin layer 6 is not thermally damaged. Further, such a short-wavelength laser absorbs almost all energy up to the depth at which the insulating resin layer 6 is removed.
By setting the removal depth by the excimer laser or more, the first back electrode 5 in the separation unit 10 is not irradiated with the laser beam EB. Therefore, the separation unit 10
In this case, the first back electrode 5 and the semiconductor layer 4 thereunder are not thermally damaged.

However, in the fifth step, an etching technique using a conventionally known metal mask may be used.

[Brief description of the drawings]

FIG. 1 is an illustrative view showing a first step of a manufacturing process of a THC photovoltaic device;

FIG. 2 is an illustrative view showing a second step in a manufacturing process of the THC type photovoltaic device;

FIG. 3 is an illustrative view showing a third step in a manufacturing process of the THC type photovoltaic device;

FIG. 4 is an illustrative view showing a fourth step of the manufacturing process of the THC photovoltaic device;

FIG. 5 is an illustrative view showing a fifth step of the manufacturing process of the THC type photovoltaic device;

FIG. 6 is an illustrative view showing one example of a THC type photovoltaic device serving as a background of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photovoltaic device 2 ... Glass substrate 3 ... Transparent electrode 4 ... Semiconductor layer 5 ... Insulating resin layer 6 ... Insulating resin layer 7 ... Second back electrode 8 ... Through hole 9 ... Connection part 10 ... Separation part 11 ... Between cells Separation unit

Continuation of the front page (56) References JP-A-60-149178 (JP, A) JP-A-61-20371 (JP, A) JP-A-63-274183 (JP, A) JP-A-3-194975 (JP) , A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 31/04-31/078

Claims (1)

(57) [Claims] 1. A transparent electrode, a semiconductor layer, a first back electrode, an insulating resin layer and a second back electrode are formed on a substrate for each cell, and the second back electrode is formed on the first back surface for each cell. The second back electrode, which is connected to the transparent electrode through an electrode and a through hole formed in the semiconductor layer and is separated for each cell, is connected to the first back electrode of an adjacent cell through the insulating resin layer at a connection portion. A photovoltaic device, wherein an inter-cell separating portion for separating the semiconductor layer and the first back electrode for each cell is arranged on the transparent electrode. apparatus.