JPH01149484A - Photovoltaic device - Google Patents

Abstract

PURPOSE:Not only to improve a conductive paste material in ohmic contact with a semiconductor film but also prevent a device of this design from deteriorating in property so as to improve it in an output property and a weather resistant property by a method wherein conductive powders contained in a conductive paste material are made to have specified dimensions in diameter respectively in a lower layer contacted with a semiconductor layer and an upper layer above the lower layer. CONSTITUTION:A photoreceptive face electrode 2 of TCO, a semiconductor film 3 containing a photoactive layer, and a back electrode 4 composed of a conductive paste material are successively laminated on an insulating substrate 1. The conductive paste constituting the back electrode 4 is composed of such a two-layered structure that conductive powders 41, 41,...,5mum in the maximum diameter are diffused into a layer of phenolic resin in contact with semiconductor film 3 and conductive powders 42, 42,...10mum or more in the minimum diameter are diffused into a layer of phenolic resin above the former layer. As mentioned above, the back electrode 4 formed of a conductive paste material is made to be two-layered, 50 that a good ohmic contact can be attained by making a lower layer containing small conductive powders 41, 41,...contact the semiconductor layer 3 and a weather resistant property can be improved through a upper layer containing large conductive powders.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a photovoltaic device that performs power generation under sunlight or other light sources, light detection, color detection, etc.

(b) Prior art This type of conventional photovoltaic device was published in Japanese Patent Publication No. 53-37718.
As seen in the above publication, a light-receiving surface electrode made of a light-transmitting conductive oxide such as ITO-5nO2 and a semiconductor film including a photoactive layer are placed on a light-transmitting and insulating substrate such as glass. A
This is a structure in which back electrodes made of metal such as / are laminated in this order.

In addition, JP-A No. 61-199673 discloses that nickel can be formed as a back electrode by an inexpensive and easy printing method or spraying method instead of a metal such as A/, which requires an expensive and complicated vacuum deposition method or sputtering method. A configuration using a conductive paste material containing a conductive powder such as is shown.

(c) Problems to be solved by the invention By the way, in a photovoltaic device using a conductive paste material as a back electrode, the particle size of the conductive powder contained in the conductive paste material depends on the output characteristics and weather resistance. It was found that it affects sexuality.

FIG. 2 shows the particle size and current/voltage (IV) characteristics of the conductive powder contained in the conductive paste material used as the back electrode. In addition, the back side 14! As a reference example, the IV characteristic when a metal such as AI is used as the box is shown by a broken line.

The particle size of the conductive powder contained in the conductive paste material is 107
If wm is large, the electrical contact with the semiconductor film is poor;
As shown by the solid line, the value of the fill factor of the IV characteristic is small, and the maximum output is also low.

On the other hand, when the particle size of the desired conductive powder is as small as 1 to 2 μm, as shown by the solid line ) (P, C, T), the I-■ characteristic deteriorates as shown by the solid line 0.

As mentioned above, when the particle size of the conductive powder contained in the conductive paste material is large, the I-V characteristics are poor, and when the particle size is small,
Although the initial IV characteristics are excellent, the weather resistance is poor.

B) Means for Solving the Problems The present invention is a photovoltaic device in which a light-receiving surface electrode, a semiconductor film including a photoactive layer, and a back electrode made of a conductive paste material containing conductive powder are laminated. The conductive paste material is characterized in that it contains conductive powder having a particle size of 10 μm or more from the side in contact with the semiconductor film and 10 μm or more from the upper side.

(E) Function According to the present invention, the conductive paste material containing the small-diameter conductive powder makes ohmic contact with the semiconductor film, and the conductive paste material containing the large-diameter conductive powder exhibits r# weatherability. Give.

(f) Example FIG. 1 is a schematic cross-sectional view showing an example of the present invention, in which a TC
A semiconductor film (3) mainly made of amorphous silicon and a back electrode (4) made of a tetraelectric paste material are present. They are stacked in this order. The conductive paste material constituting the back electrode (4) is a semiconductor film (
3] On the side in contact with the conductive powder (υf41) with an average particle size of nickel of l ~ 2 μm, 1 large particle size of 5 μm, and above it, an average particle size of nickel of lO ~ 20 μm% maximum particle size of 30 μm It has a two-layer structure in which conductive powder @2(6)... is mixed into phenolic resin.

In this way, by forming the back electrode (4) made of conductive paste material into a two-layer structure, a small diameter conductive powder circle (4υ
By contacting the lower layer containing... with the semiconductor film (3), a good ohmic contact can be formed, and the upper layer containing large-diameter conductive powder @2 (4B...) provides weather resistance. .

When the I-V characteristics of the photovoltaic device of the Praying Tree Example were measured, as shown by the solid line ■ in Figure 2, it was the same as when all of the conductive powder contained in the conductive paste material was made small in diameter. It had excellent I-V characteristics, and even when subjected to P, C, and T at 120° C. for 1 hour, the characteristics did not deteriorate at all.

In addition, in order to obtain desired output characteristics and weather resistance, the thickness of the lower layer including small diameter conductive powder + 411 (4υ...) should be 20μ.
The thickness must be less than m, and if it is thicker than this, P,
The I-■ characteristics deteriorated due to C and T.

(G) Effects of the Invention According to the present invention, the particle size of the conductive powder enriched in the conductive paste material used as the back electrode is set to 5 μm or less in the lower layer in contact with the semiconductor film. By making good ohmic contact and making the thickness of the upper layer above the lower layer 10 μm or more, deterioration of characteristics can be prevented, and therefore excellent output characteristics and weather resistance can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing IV characteristics. (2)... Light-receiving surface 'tj & pole, (3)... Semiconductor film, (4)... Back electrode, f411! 42... Conductive powder.

Claims (1)

[Claims] 1) A photovoltaic device in which a light-receiving surface electrode, a semiconductor film including a photoactive layer, and a back electrode made of a conductive paste material containing conductive powder are laminated, wherein the conductive paste material is on the side in contact with the semiconductor film. or less than 5μm, and the upper side is 10μm or less.
A photovoltaic device comprising conductive powder having a particle size of μm or more.