[20a-234B-1~10] 22.1 Joint Session M "Phonon Engineering"

▼ [20a-234B-6] Investigation of the Electron Mobility in La-doped BaSnO₃ films using Time-Domain Thermoreflectance (TDTR) Method

〇(P)HaiJun Cho¹, Mian Wei¹, Bin Feng², Anup Sanchela¹, Yuichi Ikuhara², Hiromichi Ohta¹ (1.Hokkaido University, 2.University of Tokyo)

Keywords:Transparent semiconductor oxide, Thermal conductivity, Time-domain thermoreflectance

La-doped BaSnO₃ (LBSO) is one of the most intensely studied transparent oxide semiconductors since its bulk single crystal exhibits a very high electron mobility of 320 cm² V^-1 s^-1, which is comparable to that of doped silicon. However, the electron transport properties of the reported LBSO thin films are strongly suppressed compared to single crystal values (< 100 cm² V^-1 s^-1). While most studies attribute this phenomenon to the threading dislocations originated from the lattice mismatch at film/substrate, our studies suggest that the electron transport properties of LBSO films are also strongly dependent on the film thickness and possibly the oxygen deficiency. Since oxygen deficiency affect lattice vibrational properties, in this research, we further investigate the possibility of oxygen deficiency in the LBSO films with their thermal transport properties, which will be of great value in clarifying the thickness dependence of electron mobility in LBSO films.