FABRICATION OF POLYCRYSTALLINE SILICON FILMS USING PLASMA SPRAY METHOD

We have developed a new fabrication technique of poly-crystalline sili con (poly-Si) sheet for solar cells, namely the DC-RF hybrid plasma sp ray method. It has some advantages such as high deposition rate of mor e than 10 mu m/s and large grain size of the obtained poly-Si films. P oly-Si films with a grain size of more than 20 mu m and a defect densi ty of 10(6)-10(7) cm(-2) have been obtained at the initial stage trial . The solar cell conversion efficiency of 4.3% has been obtained using the plasma sprayed poly-Si. It is considered that the reasons for the low conversion efficiency are metallic impurity contamination, region s of micro grain due to rapid nucleation and many defects in the films due to thermal stress.