Velocity saturation in La-doped BaSnO3 thin films

• Published in: Applied physics letters 2019-08, Vol.115 (9)
• Main Authors: Chandrasekar, Hareesh, Cheng, Junao, Wang, Tianshi, Xia, Zhanbo, Combs, Nicholas G., Freeze, Christopher R., Marshall, Patrick B., McGlone, Joe, Arehart, Aaron, Ringel, Steven, Janotti, Anderson, Stemmer, Susanne, Lu, Wu, Rajan, Siddharth
• Format: Article
• Language: English
• Subjects: Applied physics; Barium stannate; Carrier density; Charge density; Charge materials; Electronic devices; Perovskites; Phonons; Saturation; Semiconductor devices; Thin films; Transistors; Transport properties; Velocity
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.5097791

BaSnO3, a high mobility perovskite oxide, is an attractive material for oxide-based electronic devices. However, in addition to low-field mobility, high-field transport properties such as the saturation velocity of carriers play a major role in determining the device performance. We report on the experimental measurement of the electron saturation velocity in La-doped BaSnO3 thin films for a range of doping densities. The predicted saturation velocities based on a simple LO-phonon emission mode, using an effective LO phonon energy of 120 meV show good agreement with the measurements of velocity saturation in La-doped BaSnO3 films. Density-dependent saturation velocity in the range of 1.8 × 107 cm/s reducing to 2 × 106 cm/s is predicted for δ-doped BaSnO3 channels with carrier densities ranging from 1013 cm−2 to 2 × 1014 cm−2, respectively. These results are expected to aid the informed design of BaSnO3 as an active material for high-charge density electronic transistors.