Spectral dependence of time-resolved photoreflectance of InN epitaxial films

Femtosecond pulses at wavelengths ranging from 750 to 900 nm (1.38-1.65 eV) were used in the excitation and probing of ultrafast carrier dynamics in InN epitaxial films. Experimental results show that the hot electron relaxation rate increases with increasing electron energy, which is measured as E(0.53). This observation agrees with the prediction of electron-electron scattering relaxation mechanism. In addition, the electron-hole recombination rates are independent of the electron energy and have values of similar to 7 x 10(9) Hz. We attribute this result to the Auger recombination in InN being insensitive to temperature. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3246156]