Abstract:
For three groups of polycrystalline semiconductor films, an experimental investigation of the effect of the light-incidence angle with respect to the substrate plane on the amplitude and sign of the anomalous photovoltage is carried out. According to the previously developed theory, films are investigated in which there is the possibility of providing depleting band bending at the crystallite boundaries, inversion band bending with preservation of the overbarrier current-transport mechanism, and inversion band bending with the current-transport mechanism along the inversion channels. All three types of crystallite boundaries are found in $n$-PbTe films. It is experimentally established that, for the first and third types of boundaries, a sign inversion of the anomalous photovoltage is observed; for the second type of inversion, it is not observed. The Si films belong to the first type, where only depleting band bending is possible; the sign inversion of the anomalous photovoltage is observed there. The complete agreement between theory and experiment is established.