Electron paramagnetic resonance study of a native acceptor in as‐grown ZnGeP2

Electron paramagnetic resonance (EPR) has been used to investigate an acceptor in as‐grown single crystals of ZnGeP2. The spectra are characterized by equally spaced triplets with 1:2:1 intensity ratios representing hyperfine interactions (varying from 35 to 55 G in magnitude) with two equivalent phosphorous nuclei. Their angular dependence shows that there are four crystallographically equivalent orientations of the defect. The principal values of the g matrix are 2.002, 2.021, and 2.074 and the corresponding principal axes, at one of the four sites, are the [011], [100], and [011] directions, respectively. Two possible models are suggested for this acceptor: Either a zinc vacancy (VZn) or a zinc ion on a germanium site (ZnGe). It also is suggested that the acceptor responsible for the EPR signal is the same acceptor, namely AL1, that gives rise to a dominant near‐infrared absorption band.