Varghese A, Pandey AH, Sharma P, Yin Y, Medhekar NV, Lodha S. Electrically Controlled High Sensitivity Strain Modulation in MoS
2 Field-Effect Transistors via a Piezoelectric Thin Film on Silicon Substrates.
NANO LETTERS 2024;
24:8472-8480. [PMID:
38950892 PMCID:
PMC11262308 DOI:
10.1021/acs.nanolett.4c00357]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 05/15/2024] [Accepted: 05/16/2024] [Indexed: 07/03/2024]
Abstract
Strain can modulate bandgap and carrier mobilities in two-dimensional (2D) materials. Conventional strain-application methodologies relying on flexible/patterned/nanoindented substrates are limited by low thermal tolerance, poor tunability, and/or scalability. Here, we leverage the converse piezoelectric effect to electrically generate and control strain transfer from a piezoelectric thin film to electromechanically coupled 2D MoS2. Electrical bias polarity change across the piezo film tunes the nature of strain transferred to MoS2 from compressive (∼0.23%) to tensile (∼0.14%) as verified through Raman and photoluminescence spectroscopies and substantiated by density functional theory calculations. The device architecture, on silicon substrate, integrates an MoS2 field-effect transistor on a metal-piezoelectric-metal stack enabling strain modulation of transistor drain current (130×), on/off ratio (150×), and mobility (1.19×) with high precision, reversibility, and resolution. Large, tunable tensile (1056) and compressive (-1498) strain gauge factors, electrical strain modulation, and high thermal tolerance promise facile integration with silicon-based CMOS and micro-electromechanical systems.
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