Estimation of carrier life time from intrinsic photoluminescence of ZnO

Abstract

Comprehensive knowledge of the optical properties, particularly of the room temperature (RT) photoluminescence (PL), of ZnO is essential for the future employment of this wideband gap (~3.3 eV at 300 K) II-VI compound semiconductor in photonic and optoelectronic device structures [1]. Hence, vigorous research activities on ZnO thin films, epilayers, and crystals took place during the last two decades, encompassing a vast variety of effects and phenomena such as birefringence, photocurrent, PL including sub-band gap emission, reflectance, transmittance, excitonic properties, Raman modes, and absorption edge steepness [1-4]. However, despite that large body of knowledge and its essential importance for light emitting processes, a discussion of the ZnO PL lineshape is not found in the literature [5].