Studies of carrier dynamics in In_xGa_1-xAs_1-yN_y by picosecond Raman spectroscopy

Non-equilibrium electron distributions and energy loss rate in a metal-organic chemical vapor deposition-grown In_xGa_1-xAs_1-yN_y (x = 0.03 and y = 0.01) epilayer on GaAs substrate have been studied by picosecond Raman spectroscopy. It is demonstrated that for electron density n≅10¹⁸ cm^-3, electron distributions can be described very well by Fermi-Dirac distributions with electron temperatures substantially higher than the lattice temperature. From the measurement of electron temperature as a function of the pulse width of excitation laser, the energy loss rate in In_xGa_1-xAs_1-yN_y is estimated to be 64 meV/ps. These experimental results are compared with those of GaAs.