Study On The Polycrystalline Silicon Thin Film Solar Cells On Ceramics

To reduce cost and accelerate the industralization course of solar cell, developing thin film solar cell is the hotspot of PV research. The fabrication of poly-crystalline silicon thin film solar cell on ceramic substrates is studied in this thesis.Firstly, the physical properties of ceramic materials are analysed and silicon films are deposited on these ceramic substrates. It is found that the film deposting on Al₂O₃ and SiSiC substrates is compact and the grain is small. It is suitable for next ZMR process.In ZMR process, the effect of substrate temperature on recrystallization of silicon film is studied. It is found that the temperature gradient of solidifying front edge could be reduced by reducing focused lamp intensity and increasing substrate temperature.so the defects, such as sub-bondaries, will be reduced.Different ZMR processes are studied. It is found that thin films with barrier layers and caping layers will lead to better results. Silicon is epitaxied on these ZMR samples. The largest grain is 5 mm wide and some centimeters long.The structure and electrical properties of silicon film after ZMR are studied. It is found that film has obvious preference orientation. The resistivity of the film decreases about one order magnitude, carrier concentration increases but Hall mobility increases too. It explained that ZMR could reduce crystal boundaries and increase film quality.Polysilicon film solar cells are fabricated on Al₂O₃ and SiSiC substrates. Thin film solar cell on SiSiC substrate have best efficency of 2.06% (Voc: 230.4mv;Isc: 8.21mA/cm2;FF: 0.3305: 1 .cm2)。There is a wide gap between this result and the best result in the world, but it has not been reported in China.