Correlation between electrical and photoluminescence measurements in high-quality p-type CdTe

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Abstract
High‐quality p‐type CdTe crystals grown by the gradient freeze method were characterized by the radial resistivity distribution, Hall‐effect, and photoluminescence (PL) measurements. These measurements were performed over the crystal ingot as a function of position along the growth direction. The resistivity and the carrier concentration monotonically varied from 200 to 20 Ω cm and from 1×1014 to 1×1015 cm−3 along the growth direction, respectively. All photoluminescence spectra measured have well‐resolved spectra. It was found that both the resistivity and the carrier concentration strongly correlate to the photoluminescence intensity ratios of the neutral donor‐bound to the neutral acceptor‐bound exciton lines. The Hall mobility slightly decreased along the growth direction, and this result corresponded to the broadening of one longitudinal‐optic‐phonon replica of free excitons in the PL spectra. This good correspondence between the electrical properties and the PL spectra has provided useful means for characterizing the high‐quality CdTe. The electrical properties in high‐quality p‐type CdTe was dominated mainly by Cd vacancy/donor complexes, which act as shallow acceptors, due to a deviation from the stoichiometry.