CN102148283A

CN102148283A - Method for preparing N-type solar battery by one-step diffusion

Info

Publication number: CN102148283A
Application number: CN2010102947582A
Authority: CN
Inventors: 张学玲
Original assignee: Changzhou Trina Solar Energy Co Ltd
Current assignee: Changzhou Trina Solar Energy Co Ltd
Priority date: 2010-09-28
Filing date: 2010-09-28
Publication date: 2011-08-10

Abstract

The invention relates to a method for preparing an N-type solar battery by one-step diffusion. N-type pulling monocrystal silicon is taken as a matrix; a positive pyramid suede structure is distributed on the surface of a silicon chip randomly; a surface field which is prepared by phosphorous diffusion of an SiN antireflection coating is covered on the right side of the silicon chip; a silver metal electrode is printed on the surface field; and a P-type emitter junction which is prepared by diffusion of an Al layer is formed on the back side of the silicon chip. The surface field and the emitter junction are diffused in a high-temperature chain diffusion furnace at the same time, or diffused by introducing POC13 into a tubular diffusion furnace. The method has a simple technological process, low cost and high photoelectric conversion efficiency, and is easy to control.

Description

The diffusion of one step prepares the method for N type solar cell

Technical field

The present invention relates to a kind of production method of solar cell, especially a kind of production method of passing through a step diffusion method realization emitter and surface field.

Background technology

At present, the crystal silicon solar that domestic each big Sunpower Corp. produces can battery all be a P-type silicon substrate, but because n-type silicon substrate is comparatively big to the repellence of magazine, and there is not the photo attenuation problem, can obtain higher efficient in theory, in fact German, the U.S., developed countries such as Japan are to the attention of regenerative resource especially solar energy resources, obtaining very big breakthrough aspect the research of n-type solar cell and the production, announce as German Fraunhofer solar energy system research institute (Fraunhofer ISE), this mechanism's development with n type monocrystaline silicon solar cell, its conversion efficiency has reached 23.4%.The n-type back contact solar cell of U.S. Sunpower company, its peak efficiency reaches 24.3%, it has realized volume production for many years, in addition, the HIT battery of SANYO GS company, its conversion efficiency reaches 23%, and volume production, but, said n-type solar battery process process complexity, cost height.Under these circumstances, the N type crystal-silicon solar cell meaning of research and the suitable large-scale production of production is very great.

Summary of the invention

The technical problem to be solved in the present invention is: it is simple to propose a kind of technology, and cost is lower, is fit to the n-type silicon solar cell process of large-scale production.

The technical solution adopted in the present invention is: with n type pulling of silicon single crystal is matrix, there is the positive pyramid suede structure of random distribution on the surface, the front of silicon chip is the surface field that is coated with the phosphorous diffusion preparation of SiN antireflective film, be to be printed on the silver metal electrode on the surface field, the back side is the P-type emitter junction that AL layer diffusion preparation is arranged.Surface field and emitter junction are to spread simultaneously in high temperature chain type diffusion furnace, or put into that the logical POCl3 of tubular diffusion furnace diffuses to form.

Concrete processing step is:

1) silicon chip surface is cleaned, and form positive pyramid suede structure at silicon chip surface;

2) in silicon chip back side evaporation or sputtered aluminum layer;

3) clean removal surfactant suspension particle with hydrochloric acid, use washed with de-ionized water then;

4) starch at silicon chip positive spraying phosphoric acid or printing phosphorus, silicon chip is spread in high temperature chain type diffusion furnace or put into tubular diffusion furnace and spread, form surface field and emitter junction simultaneously at silicon chip surface by POCl3;

5) PSG cleans, positive plating SiN antireflective film, and printing front electrode and sintering are used the laser ablation edge then.

The thickness of the aluminium lamination further, step 2 of the present invention) is 2～10 microns, and the concentration of hydrochloric acid in the step 3) is 4%～7%.

The invention has the beneficial effects as follows: technical process is simple, control easily, and cost is low, the photoelectric conversion efficiency height.

Embodiment

The present invention is further detailed explanation in conjunction with the preferred embodiments now.

Select n type pulling of crystals silicon chip, crystal face (100), doping content 12 Ω cm.

Silicon chip is handled through conventional surface clean and positive pyramid surface-texturing.

Carrying out evaporation or sputter then, to form thickness be 5 microns aluminium lamination, cleans with the HCl of concentration 5% and remove suspension Al particle.

Positive spraying phosphoric acid and oven dry.

Put into high temperature chain type diffusion furnace and spread simultaneously, 25ohm/Sq is become in the emission of diffusion back, and surface field is the square resistance of 80ohm/Sq.

With concentration is that 5% HF acid is at room temperature cleaned 1min and removed PSG.

Positive deposition 90nm, refractive index is 2.11 SiNx:H film.

Positive printed silver slurry grid line, sintering, laser ablation makes edge insulation.

Final test efficient is 18%.

Just the specific embodiment of the present invention of describing in the above specification, various not illustrating is construed as limiting flesh and blood of the present invention, the person of an ordinary skill in the technical field after having read specification can to before described embodiment make an amendment or be out of shape, and do not deviate from essence of an invention and scope.

Claims

1. a step is spread the method for preparing N type solar cell, it is characterized in that may further comprise the steps:

2) in silicon chip back side evaporation or sputtered aluminum layer;

2. step diffusion as claimed in claim 1 prepares the method for N type solar cell, and it is characterized in that: described silicon chip is a N type pulling of crystals silicon chip.

3. spread the method for preparing N type solar cell as claim 1 or 3 described steps, it is characterized in that: the thickness of the aluminium lamination described step 2) is 2～10 microns.

4. spread the method for preparing N type solar cell as claim 1 or 3 described steps, it is characterized in that: the concentration of hydrochloric acid in the described step 3) is 4%～7%.

5. step diffusion as claimed in claim 1 prepares the method for N type solar cell, it is characterized in that: after back side evaporation or sputtered aluminum layer are also washed suspended particulate off with 4%～7% hydrochloric acid, positive again spraying phosphoric acid or printing phosphorus slurry, in high temperature chain type diffusion furnace, spread simultaneously, or put into the logical POCl3 diffusion of tubular diffusion furnace, form surface field and emitter junction simultaneously.