非晶半导体超晶格薄膜的光声谱研究

本文对a-Si:H/a-SiN_x:H超晶格薄膜进行了光声谱研究.在光声谱中可以观察到由于量子尺寸效应所引起的吸收边“兰移”现象.将超晶格系列样品的光声谱与它们的光吸收谱以及本征硅的光声谱作了比较,研究表明,在a-Si:H/a-SiN_x:H超晶格中光生载流子(电子和空穴)的非辐射复合比本征硅要大得多.光生载流子在带间的跃迁主要属于辐射跃迁,在带尾间的跃迁,主要属于非辐射跃迁.

Studies on Photoacoustic Spectra of Amorphous Semiconductor Superlattice Films

A series of a-Si:H/SiN_x:H superlaltice films has been studied by photoacoustic spectroscopy. The "blue shif" phenomena induced by the quantum size effect have been observed in photoacoustic spectra. Comparing the results of photoacoustic spectra with the optical absorption spectra for the same samples as well as with the photoacoustic spectrum of a intrinsic crystal silicon (C-Si) wafer, it is shown that the nonradiative recombination of the photogenerated carriers (electrons and holes) in a-Si:H/a—SiN_x:H superlattices is much larger than that of intrinsic silicon. Also, it is shown that the majority of the transitoins between bands belong to radiative transitions and the majority of the transitions between band tail states belong to nonradiative ones.