Study on the Ultrafast Carrier Dynamics in the Bulk In0.265GaN Thin Film

AbstractThe concepts of third generation solar cells critically depend on the dynamics of ultrafast carrier relaxation and electron-phonon interactions on very short times scales. The hot carrier solar cell is a type of third generation cell which especially depends on the reduction in the energy relaxation rate in an absorber material. We investigated the ultrafast carrier dynamics in 1μm bulk In0.265GaN thin film grown by a new thin-film growth technique called energetic neutral atom-beam lithography/epitaxy (ENABLE) which was done by our collaborators in the Los Alamos National laboratory(LANL), US. Characterization including steady state photoluminescence (SSPL), time-resolved photoluminescence (TRPL) and transient absorption (TA) in the time scale of picoseconds have been measured and analysed. It indicates the overall relaxation time of our sample is about 22.42ps through the Maxwell-Boltzmann approximation. This indicates that the mechanisms are mediated by the Indium content. Moreover, the indium fluctuation introduced extrinsic energy states in the forbidden energy as observed through TRPL