A first-principles study of structural, elastic, electronic, and transport properties of Cs2Te

Fuente: arXiv
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Main Authors: Wang, Gaoxue, Zhang, Jinlin, Huang, Chengkun, Dimitrov, Dimitre A., Alexander, Anna M., Simakov, Evgenya I
Format: Preprint
Published: 2024
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author Wang, Gaoxue
Zhang, Jinlin
Huang, Chengkun
Dimitrov, Dimitre A.
Alexander, Anna M.
Simakov, Evgenya I
author_facet Wang, Gaoxue
Zhang, Jinlin
Huang, Chengkun
Dimitrov, Dimitre A.
Alexander, Anna M.
Simakov, Evgenya I
contents The pursuit to operate photocathodes at high accelerating gradients to increase brightness of electron beams is gaining interests within the accelerator community. Cesium telluride (Cs2Te) is a widely used photocathode material and it is presumed to offer resilience to higher gradients because of its wider band gap compared to other semiconductors. Despite its advantages, crucial material properties of Cs2Te remain largely unknown both in theory and experiments. In this study, we employ first-principles calculations to provide detailed structural, elastic, electronic and transport properties of Cs2Te. It is found that Cs2Te has an intrinsic mobility of 20 cm2/Vs for electrons and 2.0 cm2/Vs for holes at room temperature. The low mobility is primarily limited by the strong polar optical phonon scattering. Cs2Te also exhibits ultralow lattice thermal conductivity of 0.2 W/(m*K) at room temperature. Based on the energy gain/loss balance under external field and electron-phonon scattering, we predict that Cs2Te has a dielectric breakdown field in the range from ~60 MV/m to ~132 MV/m at room temperature dependent on the doping level of Cs2Te. Our results are crucial to advance the understanding of applicability of Cs2Te photocathodes for high-gradient operation.
format Preprint
id arxiv_https___arxiv_org_abs_2405_04398
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A first-principles study of structural, elastic, electronic, and transport properties of Cs2Te
Wang, Gaoxue
Zhang, Jinlin
Huang, Chengkun
Dimitrov, Dimitre A.
Alexander, Anna M.
Simakov, Evgenya I
Materials Science
The pursuit to operate photocathodes at high accelerating gradients to increase brightness of electron beams is gaining interests within the accelerator community. Cesium telluride (Cs2Te) is a widely used photocathode material and it is presumed to offer resilience to higher gradients because of its wider band gap compared to other semiconductors. Despite its advantages, crucial material properties of Cs2Te remain largely unknown both in theory and experiments. In this study, we employ first-principles calculations to provide detailed structural, elastic, electronic and transport properties of Cs2Te. It is found that Cs2Te has an intrinsic mobility of 20 cm2/Vs for electrons and 2.0 cm2/Vs for holes at room temperature. The low mobility is primarily limited by the strong polar optical phonon scattering. Cs2Te also exhibits ultralow lattice thermal conductivity of 0.2 W/(m*K) at room temperature. Based on the energy gain/loss balance under external field and electron-phonon scattering, we predict that Cs2Te has a dielectric breakdown field in the range from ~60 MV/m to ~132 MV/m at room temperature dependent on the doping level of Cs2Te. Our results are crucial to advance the understanding of applicability of Cs2Te photocathodes for high-gradient operation.
title A first-principles study of structural, elastic, electronic, and transport properties of Cs2Te
topic Materials Science
url https://arxiv.org/abs/2405.04398