CN102916060B

CN102916060B - Silicon-based thin-film solar cell and preparation method thereof

Info

Publication number: CN102916060B
Application number: CN201210435963.5A
Authority: CN
Inventors: 任慧志; 张晓丹; 赵颖; 侯国付; 许盛之
Original assignee: Nankai University
Current assignee: Nankai University
Priority date: 2012-11-05
Filing date: 2012-11-05
Publication date: 2014-11-26
Anticipated expiration: 2032-11-05
Also published as: CN102916060A

Abstract

The invention relates to a silicon-based thin-film solar cell, wherein an n-type nano-crystalline silica material with a seed layer structure is used as a back reflection electrode; the structural formula of the n-type nano-crystalline silica material is nc-SiOx:H; the thickness of the n-type nano-crystalline silica material is 20-100 nm; and the silicon-based thin-film solar cell is a p/i/n-type single-junction or multi-junction solar cell. The preparation method of the silicon-based thin-film solar cell comprises the following steps of: after depositing a thin-film cell, preparing an n-type nc-Si:H seed layer after processing an n-type non-crystalline silicon layer of the cell through plasma; and then, preparing the n-type nc-SiOx:H material. The silicon-based thin-film solar cell and the preparation method thereof disclosed by the invention have the advantages that: due to addition of the n-type nc-Si:H seed layer, crystalline fraction and conductivity of the material can be increased; the series resistance of the cell is reduced; the preparation difficulty is reduced; when being used for the back reflection electrode of the silicon-based thin-film solar cell, the material has the back reflection effect similar to ZnO; the utilization rate of entrance light of the cell is increased; furthermore, the preparation cost of the silicon-based thin-film solar cell can be reduced.

Description

A kind of silicon-based thin film solar cell and preparation method thereof

Technical field

The present invention relates to silicon-based thin film solar cell, specifically a kind of silicon-base thin-film battery solar cell and preparation method thereof.

Background technology

Along with the continuous increase of energy resource consumption, the greenhouse gas that a large amount of uses of oil and coal cause have had a strong impact on biological environment, and oil and coal resources also face exhausted condition.Therefore, seek clean regenerative resource and become day by day urgent, and solar energy is nexhaustible regenerative resource, and environmental protection tool is of great significance, effective utilization of solar energy has become the mankind's common recognition.The utilization of solar energy, especially photovoltaic power generation technology are most promising renewable energy technologies.

Silicon-based thin film solar cell saves raw material except having, it is low to consume energy, cost is low, be easy to, advantage that large area produces, also have abundant raw materials, the advantage such as pollution-free, but silicon-based thin film solar cell still to have the shortcoming that conversion efficiency is low.

The raising of the conversion efficiency of silicon-base thin-film battery, depends on the effective absorption to visible ray in solar spectrum to a great extent, and the most important effect of back reflector is to increase incident light light path in battery, is one of effective way improving light absorption.The back reflector of silicon-base thin-film battery is generally Al or ZnO/Ag/Al, ZnO/Al, ZnO/Ag/NiCr alloy etc., and ZnO adopts MOCVD and the preparation of Sputter technology conventionally, but adding of ZnO increased cost prepared by battery.

Summary of the invention

The object of the invention is, for above-mentioned existing problems, provides a kind of silicon-based thin film solar cell and preparation method thereof, and this silicon-base thin-film battery solar cell to substitute ZnO, can improve battery conversion efficiency using the nanocrystalline silica material of N-shaped as back reflector; Its preparation method technique is simple, production cost is low, is conducive to large-scale promotion application.

Technical scheme of the present invention:

A kind of silicon-base thin-film battery solar cell, using the nanocrystalline silica material of N-shaped with Seed Layer structure as back reflector, seed layer thickness is 1-30nm, the structural formula of the nanocrystalline silica material of N-shaped is nc-SiO _x: H, thickness is 20-100nm, and the type of silicon-based thin film solar cell is p/i/n type unijunction or ties more, and the structure of unijunction silicon-based thin film solar cell is: Glass/TCO/p/i/n (a-Si:H)/n (nc-Si:H)/n (nc-SiO _x: H)/Al, the structure of multijunction solar cell is: Glass/TCO/p/i/n/p/i/n ... / n (a-Si:H)/n (nc-Si:H)/n (nc-SiO _x: H)/Al or Glass/TCO/p/i/n/p/i/n ... / n (a-Si:H)/n (nc-Si:H)/n (nc-SiO _x: H)/Ag/Al.

A preparation method for described silicon-base thin-film battery solar cell, step is as follows:

1) the TCO substrate of glass substrate is put into plasma reinforced chemical vapour deposition (PECVD) equipment, deposited successively p-type Window layer, intrinsic i layer and N-shaped amorphous silicon layer;

2) the N-shaped amorphous silicon layer of using plasma treatment technology treatment of battery in PECVD equipment, technological parameter is: aura stimulating frequency 13.56-100MHz, glow power density 10-1000mW/cm ², reacting gas is hydrogen or helium, reacting gas pressure 0.1-10Torr, reaction temperature 100-300 DEG C, reacting gas plasma treatment time 10-1000S;

3) adopt PECVD technology to prepare N-shaped nc-Si:H Seed Layer, technological parameter is: in reacting gas, increase phosphine and silane, in reacting gas, silane dilution rate is less than 3%, and phosphine is less than 5% with the doping ratio of silane, aura stimulating frequency 13.56-100MHz, glow power density 10 ~ 1000mW/cm ², reacting gas pressure 0.1-10Torr, reaction temperature 100-300 DEG C, material thickness is 1-30nm;

4) adopt PECVD technology to prepare N-shaped nc-SiO _x: H back reflector, technological parameter is: in reacting gas, increase carbon dioxide, in reacting gas, silane dilution rate is less than 3%, phosphine is less than 6% with the doping ratio of silane, the flow-rate ratio of carbon dioxide and silane is less than 7, aura stimulating frequency 13.56-100MHz, glow power density 10 ~ 1000mW/cm ², reacting gas pressure 0.1-10Torr, reaction temperature 100-300 DEG C, material thickness 20-100nm;

5) adopt evaporation or sputtering method to prepare Al electrode, make silicon-base thin-film battery solar cell.

Advantage of the present invention and beneficial effect are:

This preparation method adopts PECVD deposition technique to prepare silicon-based thin film solar cell, and N-shaped amorphous silicon layer is carried out to plasma treatment, and then deposition preparation has the N-shaped nc-SiO of nc-Si:H Seed Layer structure _x: H back reflector material; Recently regulate the x value of oxygen content in nc-SiOx:H material by regulation of carbon dioxide and silane flow rate, reach the back reflection effect identical with ZnO back reflector; The effect of Seed Layer is to improve nc-SiO _x: the conductivity of H material and crystallization rate, thus the series resistance of battery can be reduced, improve battery efficiency, reduce preparation nc-SiO _x: the difficulty of H material; Apply the technique that this technology can replace MOCVD or Sputter technology making ZnO, thereby reduce battery preparation cost.

Embodiment

Embodiment:

2) the N-shaped amorphous silicon layer of using plasma treatment technology treatment of battery in PECVD equipment, technological parameter is: aura stimulating frequency 40.68MHz, glow power density 90mW/cm ², reacting gas is hydrogen, reacting gas pressure 1.2Torr, 180 DEG C of reaction temperatures, reacting gas plasma treatment time 60S;

3) adopt PECVD technology to prepare N-shaped nc-Si:H Seed Layer, technological parameter is: in reacting gas, increase phosphine and silane, in reacting gas, silane dilution rate is 0.85%, and phosphine is 2.2% with the doping ratio of silane, aura stimulating frequency 40.68MHz, glow power density 90mW/cm ², reacting gas pressure 1.2Torr, 180 DEG C of reaction temperatures, material thickness is 10nm;

4) adopt PECVD technology to prepare N-shaped nc-SiO _x: H back reflector, technological parameter is: in reacting gas, increase carbon dioxide, in reacting gas, silane dilution rate is 0.85%, phosphine is 2.2% with the doping ratio of silane, the flow-rate ratio of carbon dioxide and silane is 2, aura stimulating frequency 40.68MHz, glow power density 90mW/cm ², reacting gas pressure 1.2Torr, 180 DEG C of reaction temperatures, material thickness 60nm;

5) adopt method of evaporating to prepare Al electrode, make silicon-base thin-film battery solar cell.

This silicon-base thin-film battery solar cell, using the nanocrystalline silica material of N-shaped with Seed Layer structure as back reflector, the type of silicon-based thin film solar cell of preparation is p/i/n type unijunction or ties more, and the structure of unijunction silicon-based thin film solar cell is: Glass/TCO/p/i/n (a-Si:H)/n (nc-Si:H)/n (nc-SiO _x: H)/Al, the structure of multijunction solar cell is: Glass/TCO/p/i/n/p/i/n ... / n (a-Si:H)/n (nc-Si:H)/n (nc-SiO _x: H)/Al or Glass/TCO/p/i/n/p/i/n ... / n (a-Si:H)/n (nc-Si:H)/n (nc-SiO _x: H)/Ag/Al.Amorphous silicon/amorphous silicon germanium silicon stacked solar cell, cascade solar cell with nanocrystalline silica back reflector structure of preparation, the conversion efficiency of battery is 8.5%.With respect to the amorphous silicon/amorphous silicon germanium silicon stacked solar cell, cascade solar cell that there is no nanocrystalline silica and ZnO back reflector structure, the conversion efficiency of battery has improved 11%.

Claims

1. the preparation method of a silicon-base thin-film battery solar cell, described silicon-base thin-film battery sun electricity is using the nanocrystalline silica material of N-shaped with Seed Layer structure as back reflector, seed layer thickness is 1-30nm, and the structural formula of the nanocrystalline silica material of N-shaped is nc-SiO _x: H, thickness is 20-100nm, and the type of silicon-based thin film solar cell is p/i/n type unijunction or ties more, and the structure of unijunction silicon-based thin film solar cell is: Glass/TCO/p/i/n (a-Si:H)/n (nc-Si:H)/n (nc-SiO _x: H)/Al, the structure of multijunction solar cell is: Glass/TCO/p/i/n/p/i/n ... / n (a-Si:H)/n (nc-Si:H)/n (nc-SiO _x: H)/Al or Glass/TCO/p/i/n/p/i/n ... / n (a-Si:H)/n (nc-Si:H)/n (nc-SiO _x: H)/Ag/Al, it is characterized in that preparation process is as follows:

2) the N-shaped amorphous silicon layer of using plasma treatment technology treatment of battery in PECVD equipment, technological parameter is: aura stimulating frequency 13.56-100MHz, glow power density 10-1000mW/cm ², reacting gas is hydrogen or helium, reacting gas pressure 0.1-10 Torr, reaction temperature 100-300 DEG C, reacting gas plasma treatment time 10-1000S;

3) adopt PECVD technology to prepare N-shaped nc-Si:H Seed Layer, technological parameter is: in reacting gas, increase phosphine and silane, in reacting gas, silane dilution rate is less than 3%, and phosphine is less than 5% with the doping ratio of silane, aura stimulating frequency 13.56-100MHz, glow power density 10 ~ 1000mW/ cm ², reacting gas pressure 0.1-10 Torr, reaction temperature 100-300 DEG C, material thickness is 1-30nm;

4) adopt PECVD technology to prepare N-shaped nc-SiO _x: H back reflector, technological parameter is: in reacting gas, increase carbon dioxide, in reacting gas, silane dilution rate is less than 3%, phosphine is less than 6% with the doping ratio of silane, the flow-rate ratio of carbon dioxide and silane is less than 7, aura stimulating frequency 13.56-100MHz, glow power density 10 ~ 1000mW/ cm ², reacting gas pressure 0.1-10 Torr, reaction temperature 100-300 DEG C, material thickness 20-100nm;