Search NASA⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 2574163

First-principles study of structural, elastic, electronic, transport properties, and dielectric breakdown of Cs 2 Te photocathode

Wang, Gaoxue [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000348127257)·Zhang, Jinlin [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0009000817293061)·Huang, Chengkun [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000231768042)·Dimitrov, Dimitre Andonov [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000292743631)·Alexander, Anna Marie [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000180333582)·Simakov, Evgenya Ivanovna [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000274831152)
View original source ↗Read source document ↗Export metadata ↓

Abstract

The pursuit to operate photocathodes at high accelerating gradients to increase brightness of electron beams is gaining interests within the accelerator community, particularly for applications such as free electron lasers (FEL) and compact accelerators. Cesium telluride (Cs 2 Te) 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 Cs 2 Te 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 Cs 2 Te. It is found that Cs 2 Te has an intrinsic mobility of 20 cm 2 /Vs for electrons and 2.0 cm 2 /Vs for holes at room temperature. The low mobility is primarily limited by the strong polar optical phonon scattering. Cs 2 Te 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 Cs 2 Te has a dielectric breakdown field in the range from ~ 60 to ~ 132 MV/m at room temperature dependent on the doping level of Cs 2 Te. Our results are crucial to advance the understanding of applicability of Cs 2 Te photocathodes for high-gradient operation.

Explore related subjects

36 MATERIALS SCIENCE43 PARTICLE ACCELERATORSelectronic deviceselectronic structure

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Wang, Gaoxue [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000348127257), Zhang, Jinlin [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0009000817293061), Huang, Chengkun [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000231768042), Dimitrov, Dimitre Andonov [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000292743631), Alexander, Anna Marie [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000180333582), Simakov, Evgenya Ivanovna [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000274831152). 2025-01-22. First-principles study of structural, elastic, electronic, transport properties, and dielectric breakdown of Cs 2 Te photocathode. https://doi.org/10.1038/s41598-024-85054-z

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

DOE OSTI2026

Cyclic moisture reactivation of calcium sorbents for long duration thermochemical energy storage

The transition to a flexible and reliable energy infrastructure, using electro-thermal energy generation technologies such as geothermal, concentrated solar power, and nuclear, usually demands simultaneous advancement of thermal energy storage (TES) to support on-demand electricity generation and industrial applications while mitigating the inherent intermittency of renewable energy sources and power outages from direct energy generation. Among TES technologies, thermochemical energy storage (TCES) based on calcium looping emerges as a compelling high-power energy storage candidate due to its high reaction enthalpy, compatibility with elevated operating temperatures, and abundance of low-cost materials. However, the long-term durability of calcium-based sorbents for TCES is hindered by surface sintering and particle aggregation, leading to performance degradation over repeated thermal cycles. This study explores a moisture hydration-based strategy to regenerate a degraded calcium sorbent and mitigate performance degradation for long duration TCES. The addition of moisture transforms calcium oxide into calcium hydroxide and produces intercalation water layers, associated with a regenerated surface area and reduced calcium oxide crystallite size. Both these effects are beneficial in restoring the sorbents' reactivity for carbonization. Additionally, an optimized hydration-assisted reactivation protocol balances the recovered energy storage capacity with heating penalty required for moisture removal from hydrated samples, resulting in an enhanced energy storage capacity up to 176% compared to benchmark sorbents that undergo cycling without reactivation after 60 cycles. In conclusion, these results highlight the potential of hydration-assisted reactivation to enhance the long-term performance of TCES, providing an effective pathway to advancing electro-thermal storage technologies.

36 MATERIALS SCIENCE↗