Adsorption-controlled growth of La-doped BaSnO3 by molecular-beam epitaxy

Hanjong Paik,Masaki Uchida,David A Muller,Shunli Shang,Kyle M Shen,Bi-Cheng Zhou,Reinhard Uecker,Darrell G Schlom,Amit Verma,Edward Lochocki,Jisung Park,Mario Brützam,Nicholas Tanen,Zhen Chen,Debdeep Jena,Ariel Seidner H,Zi-Kui Liu

doi:10.1063/1.5001839

Abstract

Epitaxial La-doped BaSnO3 films were grown in an adsorption-controlled regime by molecular-beam epitaxy, where the excess volatile SnOx desorbs from the film surface. A film grown on a (001) DyScO3 substrate exhibited a mobility of 183 cm2 V−1 s−1 at room temperature and 400 cm2 V−1 s−1 at 10 K despite the high concentration (1.2 × 1011 cm−2) of threading dislocations present. In comparison to other reports, we observe a much lower concentration of (BaO)2 Ruddlesden-Popper crystallographic shear faults. This suggests that in addition to threading dislocations, other defects—possibly (BaO)2 crystallographic shear defects or point defects—significantly reduce the electron mobility.

Highlights

Transparent conducting oxides with high mobility are being studied in hopes of realizing highperformance transparent electronics.[1]
La-doped BaSnO3 has emerged as a material of interest in this arena due to its high mobility at room temperature, transparency, and stability
La-doped BaSnO3 single crystals are reported to have mobilities as high as 320 cm[2] V1 s1 at room temperature at a mobile electron concentration of n = 8 × 1019 cm3.2 La-doped BaSnO3 has a higher mobility than all mainstream semiconductors (Si, GaAs, GaN, etc.) at doping concentrations above about n = 1019 cm3, where it is degenerately doped;[3] CdO is the only transparent semiconductor with higher mobility in this doping range.[4]

Summary

Introduction

Transparent conducting oxides with high mobility are being studied in hopes of realizing highperformance transparent electronics.[1]. (Received 27 August 2017; accepted October 2017; published online November 2017)

Results

Conclusion