# Employing High-temperature-grown SrZrO$_3$ Buffer to Enhance the Electron Mobility in La:BaSnO$_3$-based Heterostructures

## TL;DR

This paper demonstrates a method to significantly improve electron mobility in La:BaSnO$_3$ heterostructures by using a high-temperature-grown SrZrO$_3$ buffer layer, enabling high-quality films on various substrates.

## Contribution

The study introduces a novel high-temperature pulsed laser deposition process for SrZrO$_3$ buffers that reduces dislocation density, enhancing electron mobility in La:BaSnO$_3$ heterostructures.

## Key findings

- Achieved room-temperature mobility of up to 157 cm$^2$V$^{-1}$s$^{-1}$.
- Dislocation density was reduced below $1.0\times 10^{10}$cm$^{-2}$.
- Effective on multiple oxide substrates with lattice mismatch.

## Abstract

We report a synthetic route to achieve high electron mobility at room temperature in epitaxial La:BaSnO$_3$/SrZrO$_3$ heterostructures prepared on several oxide substrates. Room-temperature mobilities of 157, 145, and 143 cm$^2$V$^{-1}$s$^{-1}$ are achieved for heterostructures grown on DyScO$_3$ (110), MgO (001), and TbScO$_3$ (110) crystalline substrates, respectively. This is realized by first employing pulsed laser deposition to grow at very high temperature the SrZrO$_3$ buffer layer to reduce dislocation density in the active layer, then followed by the epitaxial growth of an overlaying La:BaSnO$_3$ active layer by molecular-beam epitaxy. Structural properties of these heterostructures are investigated, and the extracted upper limit of threading dislocations is well below $1.0\times 10^{10}$cm$^{-2}$ for buffered films on DyScO$_3$, MgO, and TbScO$_3$ substrates. The present results provide a promising route towards achieving high mobility in buffered La:BaSnO$_3$ films prepared on most, if not all, oxide substrates with large compressive or tensile lattice mismatches to the film.