CN1267745A

CN1267745A - Preparation of solar energy photovoltaic material-carbon film

Info

Publication number: CN1267745A
Application number: CN 00115352
Authority: CN
Inventors: 崔容强; 周之斌; 丁正明; 庞乾俊; 贺振宏
Original assignee: Shanghai Jiaotong University
Current assignee: Shanghai Jiaotong University
Priority date: 2000-04-07
Filing date: 2000-04-07
Publication date: 2000-09-27
Anticipated expiration: 2020-04-07
Also published as: CN1141734C

Abstract

During sputtering to deposit carbon film, carbon source target material is high-purity graphite in 99.999% purity, argon with probably hydrogen for hydrogenation is used as sputtering gas source, the sputtering pressure is 0.05-10 Pa, and some gas depant may be used.

Description

The making method of solar energy photovoltaic material-carbon film

What the present invention relates to mainly is a kind of making method of solar energy photovoltaic material-carbon film.Belong to field of semiconductor materials.

The peak in the spectral response of silicon single-crystal solar cell commonly used is positioned at 0.7～0.8 μ m at present, and peak value 0.4～0.5 μ m of solar spectral, the peak value of gallium arsenide solar cell approaches the peak value of solar spectrum, than silicon solar cell improvement is arranged, but still existing unmatched problem, its reason is the peak value of response that these material inherent energy gap width have determined them.The gallium arsenide battery also with the toxic pollutant gaseous emission, has destroyed ecotope in process of production.U.S. D.C.Ingran in 1996, declared a patent (US.Patent.No.5,055,421): " amorphous hydrogenated carbon thin films photovoltaic cell ", but only mention amorphous network hydrogenant carbon film, in amorphous silicon membrane, the hydrogenant effect is the vacancy position of passivation Siliciumatom---be dangling bonds, reduce the deathnium density of photo-generated carrier, improve carrier mobility, and carbon atom is littler than Siliciumatom, in the amorphous carbon defect center to the scattering cross-section of current carrier also little than amorphous silicon material, so the carrier mobility of amorphous carbon film can reach 10 ³Cm ²V ^-1S surpasses and reaches the level of silicon single crystal, GaAs material, than the 0.1cm of non-crystalline silicon ²V ^-1S ^-1Much bigger.Hydrogenated amorphous carbonaceous resistivity height also is not suitable for doing solar energy photovoltaic material.Seeking a kind of reproducible environmental type high efficiency, low cost solar cell is the outlet of human future source of energy.

The objective of the invention is to overcome deficiency of the prior art, propose a kind of making method of solar energy photovoltaic material-carbon film.

Technical scheme of the present invention is as follows: the target that carbon film deposition source of the present invention is used is high-purity (99.999%) graphite target, the physical sputtering deposit film, argon gas is made the sputter source of the gas, maybe can mix hydrogen and do hydrogenation, sputtering pressure is in 0.05～10Pa scope, and method has: radio-frequency sputtering, magnetically controlled DC sputtering, ion beam sputtering etc., and optional gaseous state doped source is as doping agent during sputter, during as nitrating, select NH ₃Or N ₂Gas.

Concrete technical scheme is:

1, the carbon-to-carbon atom is with the formed hydridization (SP of diamond form ³) and the carbon-to-carbon atom with the formed hydridization (SP of graphite form ²) control of hybrid bond composition: by the substrate bias in the control sputtering technology, RF, d.c. sputtering may command incide the charged argon ion pair substrate bombarding energy on the substrate, control SP ³, SP ²The hybrid bond composition, the argon ion energy is at 100ev usually, and perhaps substrate bias can obtain SP at 110v～120v ³Feng Fu film the most.

2, SP ²The control of family of group size by control sputtering technology power and bias voltage size combination control sputtering pressure, can change the SP in the film ²The size of family of group, sputtering pressure is big more, SP ²Group's family size is big more, but the flintiness of film obviously weakens, and air pressure is selected within 0.1～10Pa usually.Substrate bias is at 90v～100v, SP ²Family of group is less, and when being biased in 100v～110v, SP ²Family of group is bigger.

3, the control of resistivity: nitrogen mixes by film is done, boron mixes and phosphorus doping, can reduce the resistivity of film or improve photoconductive gain, nitrogen mixes and is realized by nitrating gas in the argon gas, the sputter mixed gas is by volume ratio 10～30vol% proportioning in total gas of nitrogen in sending into sputtering chamber, and boron, phosphorus doping are to select for use high purity boron, phosphorus powder (99.999%) to mix respectively according to a certain ratio in the high purity graphite powder, and compacting sintering is shaped.

According to technique scheme, embodiments of the invention are as follows:

1, nitrating amorphous carbon and monocrystalline silicon heterojunction: with magnetically controlled DC sputtering prepared amorphous carbon-film, the nitrating amorphous carbon is a n type conductive film material, form heterojunction with p type single crystal silicon, have rectification characteristic, under the illumination, has photovoltaic property, make the side to light gate electrode with evaporation silver, the back side is ag paste electrode, under the AM1.5 illumination, open circuit voltage reaches 300mV, and short-circuit current reaches 20mA/cm ²

2, nitrating amorphous carbon and CuInSe ₂Polycrystal film forms heterojunction, is equipped with one deck polycrystalline P type CuInSe with the plating legal system on metal substrate ₂Film forms heterojunction with radio-frequency sputtering process deposits one deck nitrating amorphous carbon thereon again; Open circuit voltage reaches 170mV.

3, spray layer of transparent conductive indium, tin-oxide film with chemical vapor deposition process commonly used earlier on glass substrate, resistivity is 3～8 * 10 ^-3Ω cm; Use magnetically controlled DC sputtering process deposits one deck nitrating amorphous carbon more thereon, the heterojunction of formation, open-circuit reaches 22mV.

The present invention has significant effect, in radio-frequency sputtering and the magnetically controlled DC sputtering technology, can change the size of substrate bias, in 100V～150V scope, obtains SP³Be the amorphous carbon-film of 80% composition, and in ion beam sputtering, regulate ion beam and plunder the total amount that is mapped on the substrate and the energy of ion beam, can control SP³The content of composition, the SP of film³Composition can be measured SP with the LR laser raman displacement³、SP ²Become Part variation, can change hardness and the light transmission of film. Adopt technology of the present invention, SP³Content exists 30%～80% interior adjusting. By changing reative cell sputtering pressure and substrate bias, can change SP²The size of family of group is come the size of family of observation group with AFM, changes SP²Family of group size, increased in size can reduce local attitude energy gap, and SP²Family of group size reduction can improve its energy gap, is adjusted to be fit to photovoltaic material requirement, SP²The size of family of group is in 1nm～5nm scope.

Amorphous carbon film is made nitrogen mix, can be with 2～4 orders of magnitude of resistivity decreased of unadulterated amorphous carbon film, Nitrogen containing amorphous carbon film is N-shaped conductive semiconductor material, SP³Still account for Main Ingredients and Appearance, generally mix The amount of nitrogen is in 0.5～2atm% scope. Amorphous carbon film is made phosphorus doping also can reduce the amorphous carbon that do not mix 5 of the resistivity of film are more than the order of magnitude, and N-shaped conductiving doping amount is in 1～2.5% scope. Amorphous carbon is thin Film is made boron doped result also can reduce resistivity, reduces approximately 1～2 order of magnitude, P-type conduction.

Claims

1, a kind of making method of solar energy photovoltaic material-carbon film, it is characterized in that the target that the carbon film deposition source is used is high-purity (99.999%) graphite target, the physical sputtering deposit film, argon gas is made the sputter source of the gas, maybe can mix hydrogen and do hydrogenation, sputtering pressure is in 0.05～10Pa scope, and optional gaseous state doped source is as doping agent during sputter.

2, the making method of this solar energy photovoltaic material-carbon film according to claim 1, its feature are that also the carbon-to-carbon atom is with the formed hydridization (SP of diamond form ³), the carbon-to-carbon atom is with the formed hydridization (SP of graphite form ²) control of hybrid bond composition: by the substrate bias in the control sputtering technology, RF d.c. sputtering may command incides the charged argon ion pair substrate bombarding energy on the substrate, controls SP ³, SP ²The hybrid bond composition, the argon ion energy is at 100ev usually, and perhaps substrate bias is at 110v～120v.

3, the making method of this solar energy photovoltaic material-carbon film according to claim 1, its feature also is SP ²The control of family of group size, by control sputtering technology power and bias voltage size combination control sputtering pressure, air pressure is selected within 0.1～10Pa usually.

4, the making method of this solar energy photovoltaic material-carbon film according to claim 1, its feature also is the control of resistivity: nitrogen mixes by film is done, boron mixes and phosphorus doping, nitrogen mixes and is realized by nitrating gas in the argon gas, the sputter mixed gas is by volume ratio 10～30vol% proportioning in total gas of nitrogen in sending into sputtering chamber, and boron, phosphorus doping are to select for use high purity boron, phosphorus powder (99.999%) to mix respectively according to a certain ratio in the high purity graphite powder, and compacting sintering is shaped.