Luminescence properties of mechanically nanoindented ZnSe

In this study, we used cathodoluminescence (CL) spectroscopy to examine the CL emissions of zinc selenide (ZnSe) single crystals that had been subjected to Berkovich nanoindentation. The CL spectra of the ZnSe exhibited both impurity emission peaks (1.8–2.4 eV band) and near-bandgap emission peaks (2.68 eV). Although CL emissions were generated during four unloading/reloading cycles, the decreased intensity of the impurity emission can be explained in terms of extended dislocation nucleation and propagation during nanoindentation. The resultant dislocation and microcracks were visualized using CL mapping and transmission electron microscopy. We suspect that the formation of a hysteresis loop during the four unloading/reloading cycles was due, in part, to massive dislocation activities induced by the indenter.