@article{3b00bafa557d468f9af77082453977ee,
title = "Spatially Resolved Investigation of the Bandgap Variation across a β-(AlxGa1-x)2O3/β-Ga2O3 Interface by STEM-VEELS",
abstract = "Alloying β-(AlxGa1-x)2O3 on a β-Ga2O3 substrate results in a heterojunction with a tunable bandgap, but is often plagued by defects in the interface region. In this work, using valence electron energy loss spectroscopy combined with density functional theory calculations, we identify a high concentration of cation interstitials at a β-(Al0.2Ga0.8)2O3/β-Ga2O3 interface and measure the optical absorption edge. We find a dip in the band edge of 0.1 eV depth and a width of around 15 nm on the β-Ga2O3 side of the interface with signs of noticeable electron probe delocalization broadening and discuss defect states versus excitons as its possible origins.",
author = "Adrian Chmielewski and Ziling Deng and Parivash Moradifar and Leixin Miao and Yuewei Zhang and Akhil Mauze and Lopez, {Kleyser A.} and Wolfgang Windl and Nasim Alem",
note = "Funding Information: N.A. would like to acknowledge Prof. James Speck for initial discussions regarding this manuscript. The authors thank Prof. Roberto Myers for fruitful discussions concerning the interpretation of the measured results. The work at PSU was supported in part by the Air Force Office of Scientific Research (AFOSR) program FA9550-18-1–027. The work at OSU was supported by AFOSR program FA9550-18-1-0335. The work at UCSB was supported in part by the AFOSR program FA9550-18-1-0479 (GAME MURI, Dr. Ali Sayir, Program Manager). Any opinions, findings and conclusions or recommendations in this material are those of the authors and do not necessarily reflect the views of the United States Air Force. P.M.{\textquoteright}s and K.A.L.{\textquoteright}s work was supported by the National Science Foundation through the Penn State MRSEC, the Center for Nanoscale Science, under grant number DMR-140620. L.M.{\textquoteright}s work was supported by the Penn State Center for Nanoscale Sciences, an NSF MRSEC under the grant number DMR-2011839 (2020−2026). Publisher Copyright: {\textcopyright} 2022 American Chemical Society",
year = "2022",
month = feb,
day = "22",
doi = "10.1021/acsaelm.1c00824",
language = "English (US)",
volume = "4",
pages = "585--591",
journal = "ACS Applied Electronic Materials",
issn = "2637-6113",
publisher = "American Chemical Society",
number = "2",
}