Research On Preparation Technology Of Key Basic Materials For Thin Film Solar Cell

In recent years,the use of solar energy has become one of the hottest issues of research and development.As a core component,thin film solar cell industry is booming.Thin film solar cells are mainly composed of glass substrate,transparent conductive film,window layer,optical absorption layer.Glass substrate and transparent conductive film,as the key materials in the structure,account for more than 30%of the total cost.This thesis mainly studies the glass substrates and transparent conductive films used in thin film solar cells,specifically including:(1)The effects of Al2O3 and MgO/CaO on the structure and properties of SiO2-RO-R2O substrate glass,the glass melt refining mechanism of mirabilite and the influence of silica sand particle size on the melting quality were studied.Experiments show that the strain point of glass substrate is increased to more than 580? when the Al2O3 content is 6.0 wt.%,MgO/CaO ratio is 1,the mirabilite content is 2.5 wt.%,and the particle size of silica sand is 100?150 mesh.The technological difficulty in achieving this significant enhancement of glass strain point is moderate,allowing high strain glass substrates for CIGS thin film solar cells to be successfully produced.(2)The reaction process of silicate in R2O-Al2O3-SiO2 glasses was studied.The mechanical,chemical and technological properties of glass are improved greatly with the increase of AlI2O3 content.The content of B2O3 directly affected the structure of glass.The performance and refining effect were better when the content of B2O3 is 4.0 wt.%.A chemical strenghening process with surface compressive stress>840 MPa has been achieved for R2O-Al2O3-SiO2 glasses.A glass composition suitable for large-scale manufacturing was developed and applied to the first production line of high strength R2O-Al2O3-SiO2 in China.(3)The effects of alkaline earth metal ratio,content of GeO2 and ZrO2 on the mechanical,chemical and optical properties of B2O3-Al2O3-SiO2 glass were systematically studied.The oxide system for large-scale production was determined.The influence of upper and lower grain size limits of silica sand on melting qualitywas also investigated.The glasses produced with domestic silica sand A with grain size range of 150-200 mesh is superior to the glasses prepared with imported silica sands.The effects of single or compound refining agents,such as SnO,SnO2,sulphur oxygen system and chloro oxygen system,on the properties of the refined glass were studied systematically.The results show that when the content of refining agents was 0.05 wt.%SrSO4+0.15 wt.%SnO2,the average diameter of bubbles was 0.52 mm and the melting ratio is 18.3%,the performance is optimal.These technological achievements are being applied to industrial glass manufacturing practice.(4)The effects of the substrate temperature,heat treatment process,and processing power on the structure and properties of ITO thin films were studied.The influence mechanism of the properties of ITO conductive film was analyzed.The conductive thin films with resistivity of 1.6×10-4?·cm were prepared at power of 85 W and 410?,and at the same time,the process and properties were balanced.The results also show that the concentration of oxygen vacancy,the scattering center of oxygen vacancy,carrier concentration and the electrical performance decrease with the increase of oxygen partial pressure.(5)In room temperature the effects of target-base distance and working pressure on the structure and performance of AZO films were studied.The influencing mechanism of the of oxygen-negative ions on the structural damage of AZO films was explored and analyzed.The suede AZO film was fabricated by etching method.The resistivity of AZO film was 3.7×10-4?·cm;the visible light transmittance was 89.59%,and the degree of haze was 24.7%.These technical achievements have been applied in the actual production of the film.(6)The effects of DC power,the DC coupled RF sputtering power and working pressure on the structural,optical and electrical properties of GZO films were systematically studied.The films were prepared under the finalized and optimal conditions that,when the work pressure is 0,2 Pa and RF ratio is 80%,the resistance rate is 2.47×10-4 ?·cm and the transmittance is 84.2%.These technical achievements are being used in actual production.