硼掺杂量对P型a-Si:H膜微结构和光/电学性能的影响

Influcence of Boron-doping Amount on Microstructure,Optical and Electrical Properties of P-Type a-Si:H Films

采用等离子体增强化学气相沉积法制备了不同硼掺杂比的P型a-Si:H系列薄膜。研究了硼掺杂比对P型a-Si:H薄膜微结构和光/电学性能的影响;同时,对最优掺杂比下的P型a-Si:H薄膜进行了真空退火处理,以研究薄膜晶体结构的改变对其光/电学性能的影响。结果表明:随着硼掺杂比的增加,P型a-Si:H薄膜的非晶结构没有实质改变,但其光学带隙及电学性能均有明显变化,总结出最佳硼掺杂比为1.0%。经真空退火处理后,P型a-Si:H薄膜的有序程度明显提高,光学带隙从1.81eV降低到1.72eV,电导率提高3个数量级。薄膜的晶体结构比硼掺杂量对薄膜电学性能的改善更为显著。

A series of P-type a-Si：H films with different flow rates of borane were prepared by a plasma enhanced chemical vapor deposition method. The influence of boron-doping amount on the microstructures and properties of a-Si：H films was analyzed. The P-type a-Si：H film with the optimal boron-doped amount was annealed in vacuum so as to investigate the influence of the film crystal structure change on the properties. The results indicate that with the increase of boron-doping amount, the microstructures of P type a-Si：H films have no substantial change, and the band gaps and electrical properties appear varying. The optimum boron-doping amount was proven to be 1.0%. The band gap of a-Si：H film decreased from 1.81 to 1.72 eV and the conductivity increased by 3 orders of magnitude after annealing. The crystal structure of film could improve the electrical properties rather than the boron-doping ratio.