|
半导体学报 2005
Microstructure and Properties of CdS Polycrystalline Thin Films for Solar Cells
|
Abstract:
The properties of CdS thin films prepared by chemical bath deposition (CBD) during the reaction process are studied by XRD,AFM,XPS,and optical transmittance spectra measurements.The results show that as-deposited CdS thin films are more homogeneous,adherent and compact on the glass substrates with time.And the optical band gap values increase too,which relates to the extent of strain.In the early stages of the growth of CBD CdS thin films,they are amorphous.As deposition proceeds,the (002) reflection peak of hexagonal CdS,together with the hexagonal (100) Cd(OH) 2,starts to appear.Furthermore,the CdS thin films show a strong preferential orientation of hexagonal (002) planes,parallel to the substrates surface.Therefore,the properties of the CdS thin films with the growth mechanism are correlated.By optimizing and controlling qualities of CdS thin films in the reaction process,the photovoltaic conversion efficiencies of more than 13% are demonstrated for CdS/CdTe solar cells of 0.502cm 2 under air mass (AM) 1.5 conditions.One of these solar cells reaches the highest conversion efficiency of 13.38% for the domestic polycrystalline thin films solar cells.