Photo-Hall effect spectroscopy with enhanced illumination in p-Cd1-xMnxTe showing negative differential photoconductivity

TL;DR

This study uses photo-Hall effect spectroscopy with enhanced illumination to analyze deep levels in p-CdMnTe, revealing their positions, effects on carrier mobility, and observing negative differential photoconductivity, with implications for material characterization.

Contribution

It introduces a novel application of photo-Hall spectroscopy with enhanced illumination to accurately identify deep levels and their impact in p-CdMnTe, supported by numerical simulations.

Findings

Four deep levels identified at specific energies

Negative differential photoconductivity observed and explained

Enhanced illumination improves deep level characterization

Abstract

We studied deep levels (DLs) in p-type CdMnTe by photo-Hall effect spectroscopy with enhanced illumination. We showed that the mobility of minority and majority carriers can be deduced directly from the spectra by using proper wavelength and excitation intensity. Four deep levels with ionization energies 0.63 eV, 0.9 eV, 1.0 eV and 1.3 eV were detected and their positions in the bandgap were verified by comparison of photogenerated electron and hole concentrations. Deduced DL model was analyzed by numerical simulations with Shockley-Reed-Hall charge generation-recombination theory and compared with alternative DL models differing in the position of selected DLs relative to Ec and Ev. We showed that the consistent explanation of collected experimental data principally limits the applicability of alternative DLs models. We also demonstrated the importance of the extended operation photon fluxes used in the spectra acquisition for correct determination of DLs character. Negative differential photoconductivity was observed and studied by charge dynamic theoretical simulations.