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Main Authors: Lv, Lingtong, Ma, Qianqian, Wang, Kailu, Wen, Xin, Shen, Shengping
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2506.20379
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author Lv, Lingtong
Ma, Qianqian
Wang, Kailu
Wen, Xin
Shen, Shengping
author_facet Lv, Lingtong
Ma, Qianqian
Wang, Kailu
Wen, Xin
Shen, Shengping
contents Flexoelectricity, an electromechanical coupling between strain gradient and polarization, offers a promising dimension to enrich silicon-based devices. Although the flexoelectricity of silicon is known, some fundamental aspects remain ambiguous, such as the discrepancy between experimental results and theoretical predictions, the influence of doping concentration, and the role of the bandgap. Here, we measured the flexoelectricity of intrinsic and heavily doped Si over the temperature range of 223 -473 K. The flexoelectric coefficient is of 2.6 μC/m and barely varies with temperature in doped silicon, while in intrinsic silicon it varies by nearly two orders of magnitude from 15.2 nC/m to 1.8 μC/m as temperature increases. We show that their different temperature dependencies correspond to the temperature-insensitive donor ionization in doped silicon and the temperature-sensitive intrinsic excitation in intrinsic silicon, with the latter captured by a quantitative relationship between flexoelectricity, temperature and bandgap. Furthermore, similar experimental results on germanium (Ge) suggest the universality of this relationship in first-generation semiconductors. These findings would offer valuable reference for developing Si-based electromechanical devices, as well as understanding the strain-gradient effects on semiconductor band structures (flexoelectronics).
format Preprint
id arxiv_https___arxiv_org_abs_2506_20379
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Thermal excitation of flexoelectricity in silicon
Lv, Lingtong
Ma, Qianqian
Wang, Kailu
Wen, Xin
Shen, Shengping
Materials Science
Flexoelectricity, an electromechanical coupling between strain gradient and polarization, offers a promising dimension to enrich silicon-based devices. Although the flexoelectricity of silicon is known, some fundamental aspects remain ambiguous, such as the discrepancy between experimental results and theoretical predictions, the influence of doping concentration, and the role of the bandgap. Here, we measured the flexoelectricity of intrinsic and heavily doped Si over the temperature range of 223 -473 K. The flexoelectric coefficient is of 2.6 μC/m and barely varies with temperature in doped silicon, while in intrinsic silicon it varies by nearly two orders of magnitude from 15.2 nC/m to 1.8 μC/m as temperature increases. We show that their different temperature dependencies correspond to the temperature-insensitive donor ionization in doped silicon and the temperature-sensitive intrinsic excitation in intrinsic silicon, with the latter captured by a quantitative relationship between flexoelectricity, temperature and bandgap. Furthermore, similar experimental results on germanium (Ge) suggest the universality of this relationship in first-generation semiconductors. These findings would offer valuable reference for developing Si-based electromechanical devices, as well as understanding the strain-gradient effects on semiconductor band structures (flexoelectronics).
title Thermal excitation of flexoelectricity in silicon
topic Materials Science
url https://arxiv.org/abs/2506.20379