Transient current in amorphous, porous semiconductor-crystalline semiconductor structures

The time-of-flight technique in the weak signal mode (i.e., under conditions of small charge drift in the sample) is used to study the transient photocurrent in amorphous (porous) semiconductor-crystalline semiconductor structures. Amorphous Se-As materials, porous Si, and crystalline Si and CdSe were incorporated in the structures. The carrier drift mobilities in the amorphous and porous layers of the structures were determined. The appearance of a cusp on the curves of the transient current is shown to be caused by acceleration of carriers passing through the interface between the amorphous (porous) layer and the crystal. It is established that the carrier acceleration influences the drift mobility and the dispersion parameters. Fiz. Tekh. Poluprovodn. 32, 187–191 (February 1998)