CN101892515A - Method for preparing full-diameter and low-oxygen and carbon solar monocrystalline silicon slice - Google Patents

Abstract

The invention provides a method for preparing a full-diameter and low-oxygen and carbon solar monocrystalline silicon slice, which breaks through the limit on the diameter of the monocrystalline silicon slice, namely the diameter is developed into 12 inches from original 8 inches; and the oxygen element content and carbon element content in the monocrystalline silicon slice are reduced, and the electrical properties of the monocrystalline silicon slice are improved. The method comprises the following steps of: 1, adopting a high-purity polycrystalline silicon raw material; 2, adopting a high-purity coating quartz crucible, and furthest preventing the oxygen element from precipitating and seeping into molten silicon to generate new impurities through a reaction; 3, growing a silicon single crystal under the environment of high-purity argon and a high-specification thermal field; 4, preparing a full-diameter silicon single crystal by adopting a straight-pull type single crystal furnace; 5, butting and rounding the silicon single crystal; 6, removing an affected layer on a single crystal surface by adopting a caustic corrosion process; and 7, performing wafer cutting by utilizing a multistrand cut-off machine with a cutting line, silicon carbide and cutting fluid to produce the thin low-oxygen and carbon and high-efficiency monocrystalline silicon slice.

Description

A kind of preparation method of full-diameter and low-oxygen and carbon solar monocrystalline silicon slice

Technical field

The present invention relates to the photovoltaic field, be specifically related to a kind of preparation method of full-diameter and low-oxygen and carbon solar monocrystalline silicon slice.

Background technology

Traditional fuel energy reduces day by day, and the harm that environment is caused becomes increasingly conspicuous, and the whole world also has 2,000,000,000 people to can not get normal power supply simultaneously.In this time, the whole world has all been invested renewable energy source to sight, wishes that renewable energy source can change human energy structure, keeps long-range Sustainable development.Sun power forms the focus of paying attention to into people among this with its exclusive advantage.Abundant solar radiant energy is an important energy, is the energy inexhaustible, nexhaustible, pollution-free, cheap, that the mankind can freely utilize.

The most basic device monocrystalline silicon piece of solar cell is to be most widely used in the present photovoltaic generation, the most tangible product of effect.Because be subjected to the restriction of monocrystalline silicon piece production technology and cost factor, the diameter of monocrystalline silicon piece is difficult to break through 8 inches these high pointes, causes the raising of solar cell power generation efficient to fluctuate for a long time always.Simultaneously long because of the monocrystalline production cycle, the oxygen and carbon content in the silicon chip is higher, and the electric property of monocrystalline silicon piece is caused very big negative impact, is difficult to guarantee the raising of conversion efficiency of solar cell and the reduction of photo attenuation.

Produce the monocrystalline silicon piece of preparation major diameter, low oxygen and carbon content, can increase substantially the efficiency of conversion of solar silicon chip battery, effectively control the optical attenuation problem of battery, constantly prolong the work-ing life of solar cell, and then reduction photovoltaic generation cost, for the industrialized development of photovoltaic generation brings huge guarantee, for photovoltaic generation popularize and more advantageous conditions is created in application.

Summary of the invention

The objective of the invention is provides a kind of preparation method of full-diameter and low-oxygen and carbon solar monocrystalline silicon slice in order to overcome the deficiencies in the prior art, and this method has broken through the restriction of monocrystalline silicon piece diameter, from present 8 inches to 12 inches development; Reduce the content of oxygen carbon in the monocrystalline silicon piece, improve the electric property of monocrystalline silicon piece.

The technical solution adopted in the present invention: a kind of preparation method of full-diameter and low-oxygen and carbon solar monocrystalline silicon slice, this method may further comprise the steps:

1, adopts high-purity polycrystalline silicon raw material;

2, use high-purity coating quartz crucible, intercept separating out of oxygen element to greatest extent and infiltrate the new impurity of reaction production in the molten silicon;

3, growing silicon single crystal under high-purity argon gas and high standard thermal field environment;

4, adopt the Straight pull single crystal growing furnace to prepare large diameter silicon monocrystal;

5, silicon single-crystal is carried out butt, round as a ball processing;

6, adopt the rotten technology of alkali to remove the single-crystal surface affected layer;

7, utilize multi-line cutting machine, be aided with line of cut, silicon carbide and cutting fluid and carry out slice processing, produce the efficient monocrystalline silicon piece that surpasses thin hypoxemia carbon.

Beneficial effect: the production of major diameter single crystal silicon chip of the present invention prepares yield rate and reaches more than 92%, be not less than the yield rate of minor diameter monocrystalline silicon piece, in single crystal preparation and cutting process, shortened process period greatly because of diameter, reduced energy consumption, it is thick to have reduced sheet by the raising cutting technique, saved a large amount of subsidiary material, reduced cost, the influence of environment is compared with the production of minor diameter monocrystalline silicon piece decreased.

Embodiment

The present invention is further illustrated below in conjunction with embodiment:

The preparation method of full-diameter and low-oxygen and carbon solar monocrystalline silicon slice of the present invention comprises two big steps:

1, silicon single-crystal preparation: utilize the production of homemade efficient DRF90 czochralski crystal growing furnace to prepare silicon single-crystal, use highly purified heavy caliber quartz crucible, once charging is many, drops into homemade high-quality polycrystal raw material, and purity reaches 9N; Growing silicon single crystal under high-purity argon gas and high standard thermal field environment adopts homemade high-purity 7N argon gas, and oxygen level is less than 1.5ppma; The electric property index of assurance monocrystalline is compared with minor diameter and is significantly improved;

2, cutting monocrystalline silicon piece: silicon single-crystal is carried out butt, round as a ball processing, adopt domestic present state-of-the-art cutting technique: steel wire diameter 0.10mm, home roll slot pitch 0.303mm; Adopt the rotten technology of alkali to remove the single-crystal surface affected layer, utilize Japanese NTC442 multi-line cutting machine, be aided with homemade line of cut, silicon carbide and cutting fluid and carry out slice processing, produce the efficient monocrystalline silicon piece that surpasses thin hypoxemia carbon.

Claims (1)

1. the preparation method of a full-diameter and low-oxygen and carbon solar monocrystalline silicon slice, it is characterized in that: this method may further comprise the steps:

1, adopts high-purity polycrystalline silicon raw material;

2, use high-purity coating quartz crucible, intercept separating out of oxygen element to greatest extent and infiltrate the new impurity of reaction production in the molten silicon;

3, growing silicon single crystal under high-purity argon gas and high standard thermal field environment;

4, adopt the Straight pull single crystal growing furnace to prepare large diameter silicon monocrystal;

5, silicon single-crystal is carried out butt, round as a ball processing;

6, adopt the rotten technology of alkali to remove the single-crystal surface affected layer;

7, utilize multi-line cutting machine, be aided with line of cut, silicon carbide and cutting fluid and carry out slice processing, produce the efficient monocrystalline silicon piece that surpasses thin hypoxemia carbon.