High-Frequency Photoelectromagnetic Effect inp-Type InSb

Abstract

The high-frequency response of the photoelectromagnetic (PEM) effect in $p$-type InSb has been studied both theoretically and experimentally over the temperature range 77-203 \ifmmode^\circ\else\textdegree\fi{}K. It was found that where the response curves could be characterized by a single time constant, the curves exhibited a high-frequency falloff with a 3-dB/octave slope, in contrast to the 6-dB/octave slope which was characteristic of the photoconductive (PC) response. At temperatures around 200 \ifmmode^\circ\else\textdegree\fi{}K, the same time constant entered into both the PEM and PC response. However, around 77 \ifmmode^\circ\else\textdegree\fi{}K, the PEM time constant was at least 3 orders of magnitude smaller than the PC time constant. This difference was shown theoretically to correspond to the difference between the steady-state electron and hole lifetimes, with which the PEM and PC time constants may, respectively, be identified. The character of the PEM frequency-response curves was found to change as the temperature was increased from 77 \ifmmode^\circ\else\textdegree\fi{}K, with evidence that more than one time constant was involved over the range 104-140 \ifmmode^\circ\else\textdegree\fi{}K. All the response curves observed experimentally can be quantitatively accounted for in terms of a two-independent-level recombination model with parameters which are only slightly different from those previously used by Hollis, Choo, and Heasell.