Through a combination of thin film growth, hard X-ray photoelectron spectroscopy (HAXPES), scanning transmission electron microscopy/electron energy loss spectroscopy (STEM/EELS), magneto-transport measurements, and transport modeling, we report on the demonstration of modulation-doping of BaSnO3 (BSO) using a wider bandgap La-doped SrSnO3 (LSSO) layer. Hard X-ray photoelectron spectroscopy (HAXPES) revealed a valence band offset of 0.71 +/- 0.02 eV between LSSO and BSO resulting in a favorable conduction band offset for remote doping of BSO using LSSO. Nonlinear Hall effect of LSSO/BSO heterostructure confirmed two-channel conduction owing to electron transfer from LSSO to BSO and remained in good agreement with the results of self-consistent solution to one-dimensional Poisson and Schr\"odinger equations. Angle-dependent HAXPES measurements revealed a spatial distribution of electrons over 2-3 unit cells in BSO. These results bring perovskite oxides a step closer to room-temperature oxide electronics by establishing modulation-doping approaches in non-SrTiO3-based oxide heterostructure.
@article{arxiv.1905.04563,
title = {Separating Electrons and Donors in BaSnO3 via Band Engineering},
author = {Abhinav Prakash and Nicholas F. Quackenbush and Hwanhui Yun and Jacob Held and Tianqi Wang and Tristan Truttmann and James M. Ablett and Conan Weiland and Tien-Lin Lee and Joseph C. Woicik and K. Andre Mkhoyan and Bharat Jalan},
journal= {arXiv preprint arXiv:1905.04563},
year = {2020}
}