[23p-C206-1~12] 3.5 Ultrashort-pulse and high-intensity lasers (formerly 3.6)

[23p-C206-9] Separation of interface and substrate carrier dynamics at a heterointerface based on coherent phonons

〇Kunie Ishioka¹, E. Angerhofer², C.J. Stanton², G. Mette³, K. Volz³, W. Stolz³, U. Hoefer³ (1.NIMS, 2.Univ. Florida, 3.Univ. Marburg)

Keywords:time-resolved spectroscopy, phonon, semiconductor

We perform transient reflectivity measurements on GaP/Si(001) using a near infrared pulse, to which GaP is transparent. The Si LO phonon signal in the transient reflectivity exhibits a drastic amplitude decrease and a sign change with increasing GaP layer thickness, which can be explained by the interference of the probe light reflected at the GaP/Si interface. Based on this knowledge, we can separate the interface- and the substrate-contributions in the carrier-induced non-oscillatory transient reflectivity signal. The obtained signals reveal interfacial carrier dynamics that is dependent on the GaP layer thickness.