摘要
为阐明a-Si∶H的光致变化效应的物理机构,作者用光电流相移法研究了光照前后.a-Si∶H导带尾态的变化情况;同时用等光电导法测量了光吸收Urbach尾,从而确定了价带尾的光致变化情况.实验结果表明:光照以后,导带尾态和价带尾态都增加了.作者认为:在集团氢存在的地方,与光照引起的Si-H键断裂相伴随的Si-Si弱键的增加是带尾态增加的原因.
In order to clarify the physical mechanism of Staebler-Wronski effect (SWE) the photoin-duced change in the density of conduction band tail states of a-Si: H before and after light soa-king has been investigated by modulated photocurrent phaseshift analysis.The variation of va-lence band tail states has also been estimated from the change of Urbach edge.The experi-mental result,show an increase of both conduction and valence band tail states. It isbeleived that the increase of weak Si-Si bonds acompanying the Si-H bond breaking under il-lumination at the place where exist clustered hydrogen is the reason of increasing band tail sta-tes.
关键词
A-SI:H
光致变化
a-Si:H
Photoinduced chang
Band tail states
