Ohmic and acoustoelectric currents in the hall effect for the investigation of bipolar conductivity

Abstract

Two modifications of the Hall‐effect — for ohmic and for acoustoelectric currents — are combined and the problem is considered of the bipolar conductivity of semiconductors from this stand‐point. It is shown that 1) bipolarity exists if both the modifications of the Hall‐effect give different results at the same current; 2) the microscopic mobility of majority carriers is within the limits of mobilities obtained from these two modifications. Experiments are made using CdS single crystals under conditions of infrared quenching of photoconductivity.

Investigation of the bipolar photoconductivity in CdTe

“…The measurements for obtaining the quantities pp, p,, n, p and the examination of (6) were performed using the device for Hall-effect and HEAC investigations [4] as well as the device for the investigation of the critical electric field of the A F J current. The latter device comprises a high-voltage pulse generator and a recorder of the A E Longitudinal ultrasonic waves of 10, 30, and 60 MHz frequency were applied.…”

“…Conductivity type conversions in other materials also have been reported in [2, 31. The typical monopolar semi-insulator n-CdS may have an appreciable bipolarity under some conditions [4]. Also it is common to believe that most if not all semiconductors are bipolar under strong photoexcitation.…”