Stability of thin films of microcrystalline silicon under light soaking

Abstract:

Silicon thin films with different crystalline ratio(Xc) have been deposited by varying silane content(SC) of reactive gases in the RF-PECVD process. The effects of silane content on performance of the materials and the relationship between microstructure and opto-electronic properties were studied by means of Raman measurements, photoconductivity (σ_ph), and dark conductivity (σ_d), followed by the measurements of light absorption coefficient (α), the product of quantum efficiency, mobility and lifetime (ημτ), before, during and after light soaking, respectively. The results indicate that the microcrystalline silicon near the transition region is suitable to prepare microcrystalline silicon of device grade, and that the amorphous region of the material is responsible to the light induced degradation. This work is supported by the State Key Development Program for Basic Research of China (Grant No. G2000028202, G2000028203), the Key Project of Education Bureau (Grant No. 02167) and the State Key Development Program (2002303261)