The Preparation And Performance Investigation Of Buffer Layer And Absorbed Layer Materials For Thin Film Solar Cells

With the rapid development of human society, the energy crisis has become the most considering thing of humankind. Solar energy has been widespreadly concerned as the most environmentally, friendly, clean, inexhaustible renewable energy. CIGS thin film solar cell has the advantages of low cost, simple process and good performance, which has the same high conversion efficiency as good as silicon solar cells.This will also become the mainstream in the future.Due to the buffer layer CdS of the CIGS solar cell has a small band gap, it will absorb the light which the wavelength less than blue-ray, therefore it could affect the conversion efficiency of solar cell. The Cd1-xZnxS instead of CdS as buffer layer of the solar cell can improve CIGS solar cell conversion efficiency, reduce costs, and can decrease the use of toxic substances Cd and pollution of the environment.In this paper, the Cd1-xZnxS buffer layer materials with different proportions were prepared by chemical bath mothed, the film properties of different annealed temperatures were researched by means of XRD, SEM, ED AX, light transmittance test and so on. The results show that the film of Cd0.9Zn0.1S is suitable as a buffer layer of solar cells materials when annealed in the450℃, because the film surface is roughness and it has high light transmittance, the band gap of Eg=2.56eV, the lattice parameters a=4.08814A, c=6.66059A, and its average grain size is24.9902nm. The content of Ga element is relatively rare in the earth, which will affect costs and prospects of the development of CIGS solar cells. In CIGS, the replacement of the element Al for Ga, and the element S for Se can form the compound material Cu(InAl)(SexS1-x)2, whichnot only can expand the GIGS film band gap, but also reduce the cost of materials. It is a new direction for the future development of thin film solar cells.In addition, the article also made a preliminary exploration of absorption-layer material Cu(InAl)(SexS1-x)2. The film annealed at450℃has formed well structure after20minutes. The band gap of the film will change form1.08to1.51with the reduction of Se content and S content increases. The percent of Cu and Al elements was only about10%and2%. The missing of Cu and Al elements has become difficulty and bottleneck in this experiment, but it provides a reference for follow-up research.