Epitaxial Electrodeposition of Wide Bandgap Cuprous Bromide on Silver Via a Silver Bromide Buffer Layer

Abstract

Cuprous halides are an important class of wide bandgap p-type semiconductors used in opto-electronics. Cuprous bromide (CuBr) shows potential for short-wavelength devices due to a large exciton binding energy (108 meV) and near-ultraviolet bandgap (3.1 eV). However, the growth of high-quality epitaxial CuBr films by electrodeposition has remained a challenge. Here, we introduce a low-cost electrochemical procedure for producing epitaxial CuBr(111) on a Ag(111) substrate by a [111]-oriented silver bromide (AgBr) buffer layer. The AgBr buffer layer forms during the electrodeposition of the CuBr. The mismatch between CuBr(111) and AgBr(111) is −1.3%. A plausible mechanism for nucleation and growth of the epitaxial CuBr is proposed. X-ray techniques including high resolution X-ray diffraction and X-ray pole figures are used to determine the epitaxial relationship. CuBr(100) is also produced on a Ag(100) surface by a AgBr(100) buffer layer that is rotated in-plane 45° relative to the Ag(100) surface. This in-plane rotation reduces the lattice mismatch from +39.5% for an unrotated film to −1.4% for a 45° rotated film.

Department(s)

Chemistry

Comments

U.S. Department of Energy, Grant DE-FG02–08ER46518

International Standard Serial Number (ISSN)

1945-7111; 0013-4651

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 The Electrochemical Society, All rights reserved.

Publication Date

01 Sep 2022

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