Photo-Electrical And Transport Properties Of Hydrothermal Zno

We performed the studies of optical, photoelectric, and transport properties of a hydrothermal bulk n-type ZnO crystal by using the contactless optical techniques: photoluminescence, light-induced transient grating, and differential reflectivity. Optical studies revealed bound exciton and defect-related transitions between the donor states (at similar to 60 meV and similar to 240 meV below the conduction band) and the deep acceptor states (at 0.52 eV above the valence band). The acceptor state was ascribed to VZn, and its thermal activation energy of 0.43 eV was determined. A low value of carrier diffusion coefficient (similar to 0.1 cm(2)/s) at low excitations and temperatures up to 800K was attributed to impact the recharged deep acceptors. Electron and hole mobilities of 140 and similar to 80 cm(2)/Vs, correspondently, were determined at room temperature. The decrease of carrier lifetime with excitation was ascribed to increasing rate of radiative recombination at low temperatures and nonradiative recombination above the room temperature. (C) 2016 AIP Publishing LLC.