Optically detected magnetic resonance and optically detected ENDOR of shallow indium donors in ZnO

Resolved hyperfine structure was observed in time-resolved optically detected electron-paramagnetic-resonance (ODMR) spectra obtained via a donor-acceptor emission band of ZnO. Optically detected electron-nuclear double-resonance (ENDOR) experiments showed that the structure results from hyperfine interaction with ¹¹⁵In. The values measured for the g and hyperfine tensors (g_∥=1.957, g_⊥=1.956, A_∥h=100.3 MHz, A_⊥h=100.1 MHz) lead to attribution of the ODMR spectrum to shallow indium donors.