Carrier recombination dynamics in Si doped InN thin films

Time-integrated and time-resolved photoluminescence (PL) of InN thin films of different background carrier concentrations are investigated. The PL formation mechanism is attributed to the "free-to-bound" transition by analyzing the time-integrated PL spectra at different pump fluences. The dependence of the PL decay time with emission energy is investigated using a theoretical model which speculates upon the carrier localization in InN thin films. The radiative lifetime, mobility edge, and carrier localization energy are obtained from the dependence of the PL decay time on emission energy and are studied at different background carrier concentrations. The effect of intervalley scattering between the Gamma(1) and Gamma(3) valley on the radiative lifetime, mobility edge, and carrier localization energy is discussed. The longer radiative lifetime and smaller values of the mobility edge and localization energy for 3.06 eV excitation are observed than that for the 1.53 eV excitation due to the intervalley scattering process. (C) 2011 American Institute of Physics. [doi:10.1063/1.3607271]