Photoelectrical properties of microcrystalline silicon films

Lightly boron-doped microcrystalline silicon (muc-Si:H) films with a low da rk conductivity and a high photosensitivity are used for a systematic inves tigation of the steady-state (SSPC) and transient photoconductivity (TPC). We find that the photoelectronic properties are only determined by the crys talline components of this mixed-phase material but not by the residual amo rphous silicon (a-Si:H). Nevertheless, the behaviour of SSPC and TPC are to a great extent similar to that of a-Si:H. This suggests that in muc-Si:H t here is a similar distribution of gap states (band-tail states, dangling bo nds) as in a-Si:H. The weak dependence of SSPC on the photon flux may be du e to the presence of long-range potential fluctuations caused by inhomogene ously distributed charged defects. (C) 2001 Elsevier Science B.V. All right s reserved.