Spatially Resolved Investigation of the Bandgap Variation across a β-(Al_{x}Ga_{1–x})₂O₃/β-Ga₂O₃ Interface by STEM–VEELS

Adrian Chmielewski; Ziling Deng; Parivash Moradifar; Leixin Miao; Yuewei Zhang; Akhil Mauze; Kleyser A. Lopez; Wolfgang Windl; Nasim Alem

doi:10.1021/acsaelm.1c00824

journal article·2022-02-22

Spatially Resolved Investigation of the Bandgap Variation across a β-(Al_xGa_1–x)₂O₃/β-Ga₂O₃ Interface by STEM–VEELS

Adrian Chmielewski, Ziling Deng, Parivash Moradifar, Leixin Miao, Yuewei Zhang, Akhil Mauze, Kleyser A. Lopez, Wolfgang Windl, Nasim Alem

ACS Applied Electronic Materials· Volume 4· Issue 2

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Source abstract

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.

Source: openalex_inverted_index · Quality: baseline

Research context

Metals & alloys

OpenAlex topics: Ga2O3 and related materials · ZnO doping and properties · Advanced Photocatalysis Techniques

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Department of Materials Science and Engineering, Materials Research Institute, The Pennsylvania State University, University Park 16802, United States

Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, United States

Materials Department, University of California Santa Barbara, Santa Barbara, California 93106, United States

Funding

Air Force Office of Scientific Research · Division of Materials Research

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