Localization of the excitonic luminescence of ZnO nano-tetrapods

We present the characterization of the luminescence properties of ZnO nano-tetrapods. Low temperature, power dependence, and temperature dependence of the ZnO nano-tetrapods were investigated. From the low-temperature photoluminescence (PL), strong surface exciton emission (SX, at 3.367 eV), two-electron satellite of donor-bound exciton emission (TES, at 3.315 eV), and donor–acceptor pair emission (DAP, at 3.226 eV) are observed. Temperature dependence of those emission lines shows complex features. Delocalization due to thermal activation was observed from all emission lines, which strongly indicates that evaluation of luminescence properties of nanostructures requires special care about the localization centers for excitons.