Method for continuously preparing crystalline silicon solar cell PN (Positive-Negative) junction and antireflection film

Abstract

The invention discloses a method for continuously preparing a crystalline silicon solar cell PN (Positive-Negative) junction and antireflection film. The method comprises the following steps of depositing a phosphor-doped (or boron-doped) silicon nitride antireflection film on a P-type (or N-type) silicon wafer which is cleaned and etched by using a plasma enhanced chemical vapor deposition technology, carrying out conventional annealing treatment at high temperature so that part phosphor (or boron) in the silicon nitride layer is diffused to the P-type (or N-type) silicon wafer, and forming a PN junction on the surface of the silicon wafer. The method is compatible with the industrialized crystalline silicon solar cell production process, does not need complex POC13 or BBr3 diffusion andthe subsequent step of removing phosphorus silicon or boron silicon glass, has simpler production process and is suitable for low-cost batch production.

Description

Technical field

[0001] The present invention involves the production method of crystalline silicon solar cell PN and anti -membrane. Background technique

[0002] Crystal silicon solar cells are rich in raw materials, high photoelectric conversion efficiency, good stability, long life, and mature technology to occupy more than 80%of the photovoltaic market. How to further reduce costs is the focus of the domestic and foreign photovoltaic industry.

[0003] At present, the P -type crystal silicon solar battery production process of mature commercial production includes the following steps: surface weaving and chemical cleaning of silicon wafers, in POCL 3 In the atmosphere, PN knots are formed, the PN knit around the silicon wafer, the de -silicon glass (PSG), PECVD nitrogen -plated silicon -plated reflex film, the screen printing positive, back electrodes and back surface surfaces, sintering to form ohm contact.

[0004] In the solar battery manufacturing process, the formation o...

Examples

Embodiment 1

[0021] Example 1: The area will be 125×125mm 2 , P-type single crystal silicon wafer with a thickness of about 200 microns is textured and cleaned, and a phosphorus-doped silicon nitride film with a thickness of 50 nm is deposited by PECVD equipment, and the phosphorus atomic mass percentage in the silicon nitride film is 3% , where the deposition temperature is 300 °C, PH 3 with SiH 4 The volume flow ratio of 1:100, SiH 4 with NH 3 The volume flow ratio is 1:5, and the pressure of the reaction chamber is 100Pa; then in a nitrogen atmosphere, annealed at 900 °C for 10 minutes to achieve the surface diffusion of phosphorus and the formation of N-type emitter, and finally form a layer covered with silicon nitride PN junction.

Embodiment 2

[0022] Example 2: The area will be 156×156mm 2 , P-type polysilicon wafer with a thickness of about 180 microns is textured and cleaned, and a 200 nm thick phosphorus-doped silicon nitride film is deposited by conventional PECVD equipment. The mass percentage of phosphorus in the silicon nitride film is 5%, and the substrate temperature 400℃, PH 3 with SiH 4 The volume flow ratio of 5:100, SiH 4 with NH 3 The volume flow ratio is 1:5, and the reaction chamber pressure is 80Pa; then annealed at 850°C for 20 minutes in a nitrogen atmosphere to achieve phosphorus diffusion and N-type emitter formation, and finally form a silicon nitride layer. PN junction.

Embodiment 3

[0023] Example 3 : Set the area to 125×125mm 2 , N-type single crystal silicon wafer with a thickness of about 200 microns is textured and cleaned, and a boron-doped silicon nitride film with a thickness of 100 nm is first deposited by PECVD technology. The atomic mass percentage of boron in the silicon nitride film is 4%. The bottom temperature is 400℃, B 2 H 6 with SiH 4 The volume flow ratio of 1:100, SiH 4 with NH 3 The volume flow ratio is 1:5, and the reaction chamber pressure is 100Pa; then annealed at 1000 °C for 30 minutes in a nitrogen atmosphere to achieve B diffusion and P-type emitter formation, and finally form a PN covered with a silicon nitride layer. Knot.

Technical field

[0001] The present invention involves the production method of crystalline silicon solar cell PN and anti -membrane. Background technique

[0002] Crystal silicon solar cells are rich in raw materials, high photoelectric conversion efficiency, good stability, long life, and mature technology to occupy more than 80%of the photovoltaic market. How to further reduce costs is the focus of the domestic and foreign photovoltaic industry.

[0003] At present, the P -type crystal silicon solar battery production process of mature commercial production includes the following steps: surface weaving and chemical cleaning of silicon wafers, in POCL 3 In the atmosphere, PN knots are formed, the PN knit around the silicon wafer, the de -silicon glass (PSG), PECVD nitrogen -plated silicon -plated reflex film, the screen printing positive, back electrodes and back surface surfaces, sintering to form ohm contact.

[0004] In the solar battery manufacturing process, the formation o...

Examples

Embodiment 1

[0021] Example 1: The area will be 125×125mm 2 , P-type single crystal silicon wafer with a thickness of about 200 microns is textured and cleaned, and a phosphorus-doped silicon nitride film with a thickness of 50 nm is deposited by PECVD equipment, and the phosphorus atomic mass percentage in the silicon nitride film is 3% , where the deposition temperature is 300 °C, PH 3 with SiH 4 The volume flow ratio of 1:100, SiH 4 with NH 3 The volume flow ratio is 1:5, and the pressure of the reaction chamber is 100Pa; then in a nitrogen atmosphere, annealed at 900 °C for 10 minutes to achieve the surface diffusion of phosphorus and the formation of N-type emitter, and finally form a layer covered with silicon nitride PN junction.

Embodiment 2

[0022] Example 2: The area will be 156×156mm 2 , P-type polysilicon wafer with a thickness of about 180 microns is textured and cleaned, and a 200 nm thick phosphorus-doped silicon nitride film is deposited by conventional PECVD equipment. The mass percentage of phosphorus in the silicon nitride film is 5%, and the substrate temperature 400℃, PH 3 with SiH 4 The volume flow ratio of 5:100, SiH 4 with NH 3 The volume flow ratio is 1:5, and the reaction chamber pressure is 80Pa; then annealed at 850°C for 20 minutes in a nitrogen atmosphere to achieve phosphorus diffusion and N-type emitter formation, and finally form a silicon nitride layer. PN junction.

Embodiment 3

[0023] Example 3 : Set the area to 125×125mm 2 , N-type single crystal silicon wafer with a thickness of about 200 microns is textured and cleaned, and a boron-doped silicon nitride film with a thickness of 100 nm is first deposited by PECVD technology. The atomic mass percentage of boron in the silicon nitride film is 4%. The bottom temperature is 400℃, B 2 H 6 with SiH 4 The volume flow ratio of 1:100, SiH 4 with NH 3 The volume flow ratio is 1:5, and the reaction chamber pressure is 100Pa; then annealed at 1000 °C for 30 minutes in a nitrogen atmosphere to achieve B diffusion and P-type emitter formation, and finally form a PN covered with a silicon nitride layer. Knot.