Shi, J;
Rubinstein, EA;
Li, W;
Zhang, J;
Yang, Y;
Lee, T-L;
Qin, C;
... Zhang, KHL; + view all
(2022)
Modulation of the Bi3+ 6s2 Lone Pair State in Perovskites for High-Mobility p-Type Oxide Semiconductors.
Advanced Science
, Article e2104141. 10.1002/advs.202104141.
(In press).
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Scanlon_Advanced Science - 2022 - Shi - Modulation of the Bi3 6s2 Lone Pair State in Perovskites for High‐Mobility p‐Type Oxide.pdf - Published Version Download (3MB) | Preview |
Abstract
Oxide semiconductors are key materials in many technologies from flat-panel displays,solar cells to transparent electronics. However, many potential applications are hindered by the lack of high mobility p-type oxide semiconductors due to the localized O-2p derived valence band (VB) structure. In this work, the VB structure modulation is reported for perovskite Ba2 BiMO6 (M = Bi, Nb, Ta) via the Bi 6s2 lone pair state to achieve p-type oxide semiconductors with high hole mobility up to 21 cm2 V-1 s-1 , and optical bandgaps widely varying from 1.5 to 3.2 eV. Pulsed laser deposition is used to grow high quality epitaxial thin films. Synergistic combination of hard x-ray photoemission, x-ray absorption spectroscopies, and density functional theory calculations are used to gain insight into the electronic structure of Ba2 BiMO6 . The high mobility is attributed to the highly dispersive VB edges contributed from the strong coupling of Bi 6s with O 2p at the top of VB that lead to low hole effective masses (0.4-0.7 me ). Large variation in bandgaps results from the change in the energy positions of unoccupied Bi 6s orbital or Nb/Ta d orbitals that form the bottom of conduction band. P-N junction diode constructed with p-type Ba2 BiTaO6 and n-type Nb doped SrTiO3 exhibits high rectifying ratio of 1.3 × 104 at ±3 V, showing great potential in fabricating high-quality devices. This work provides deep insight into the electronic structure of Bi3+ based perovskites and guides the development of new p-type oxide semiconductors.
Type: | Article |
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Title: | Modulation of the Bi3+ 6s2 Lone Pair State in Perovskites for High-Mobility p-Type Oxide Semiconductors |
Location: | Germany |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1002/advs.202104141 |
Publisher version: | https://doi.org/10.1002/advs.202104141 |
Language: | English |
Additional information: | © 2021 The Authors. Advanced Science published by Wiley-VCH GmbH.This is an open access article under the terms of the Creative CommonsAttribution License, which permits use, distribution and reproduction inany medium, provided the original work is properly cited |
Keywords: | DFT calculations, electronic structures, p-type oxide semiconductors, photoemission spectroscopy |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
URI: | https://discovery.ucl.ac.uk/id/eprint/10141635 |
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