Spectral investigation of carrier recombination processes in ZnO nanorods at high temperatures

• DOI: 10.1063/1.2948938
• Publication Date: 2008-06-27T22:14:55Z
• Authors: A. Gupta; M. Omari; N. Kouklin
• Keywords: Nanorod; Atmospheric temperature range; Wide-bandgap semiconductor

The mechanism of near-band-edge (NBE) emission from crystalline ZnO (c-ZnO) nanorods grown on c-Si by a catalyst-assisted vapor-liquid-solid method has been investigated performing temperature-, power-, and time-dependent photoluminescence (PL) measurements at temperature (T) range 143–503K. In contrast to previous reports, we find that the NBE PL is primarily associated with free exciton emission, whereas contribution band-to-band free-to-bound radiative recombinations remains negligible up highest T studied. A spectral evolution band was further analyzed within framework three-parameter model, proposed recently, results presented discussed. Finally, ratio excitonic-to-defect luminescence intensity observed change nonmonotonically T, which explained based difference in quenching mechanisms defect PL.