Buffer layer-less fabrication of high-mobility transparent oxide semiconductor, La-doped BaSnO3

Abstract

Transparent oxide semiconductors (TOSs) showing both high visible transparency and high electron mobility have attracted great attention towards the realization of advanced optoelectronic devices. La-doped BaSnO3 (LBSO) is one of the most promising TOSs because its single crystal exhibits a high electron mobility. However, in the LBSO films, it is very hard to obtain high mobility due to the threading dislocations, which are originated from the lattice mismatch between the film and the substrate. Therefore, many researchers have tried to improve the mobility by inserting a buffer layer. While the buffer layers increased the electron mobilities, this approach leaves much to be desired since it involves a two-step film fabrication process and the enhanced mobility values are still significantly lower than single crystal values. We show herein that the electron mobility of LBSO films can be improved without inserting any buffer layers if the films are grown under highly oxidative ozone (O3) atmospheres. The O3 environments relaxed the LBSO lattice and reduced the formation of Sn2+ states, which are known to suppress the electron mobility in LBSO. The resultant O3-LBSO films showed improved mobility values up to 115 cm2 V-1 s-1, which is among the highest in LBSO films on SrTiO3 substrates and comparable to LBSO films with buffer layers.

16 pages including 5 figures

References in corpus (6)

• Reversible redox reactions in an epitaxially stabilized SrCoOx oxygen sponge
• High Mobility in a Stable Transparent Perovskite Oxide
• Physical properties of transparent perovskite oxides (Ba,La)SnO3 with high electrical mobility at room temperature
• Large thickness dependence of the carrier mobility in a transparent oxide semiconductor, La-doped BaSnO3
• Oxygen vacancy driven mobility enhancement in epitaxial La-doped BaSnO3 from vacuum annealing
• Thermopower modulation clarification of the intrinsic effective mass in a transparent oxide semiconductor, BaSnO3

Cited by in corpus (4)

• One-step epitaxy of high-mobility La-doped BaSnO3 films by high-pressure magnetron sputtering
• Effect of lattice distortions on the electron and thermal transport properties of transparent oxide semiconductor Ba1-xSrxSnO3 solid solution films
• $\sqrt{2}$$\times$$\sqrt{2}R45^{\circ }$ surface reconstruction and electronic structure of BaSnO${}_3$ film
• High electrical conducting deep-ultraviolet-transparent oxide semiconductor La-doped SrSnO3 exceeding ~3000 S cm-1