Strain Tune Suspended MoS₂ for Polarization Photodetection

Abstract

In situ modulation of molybdenum disulfide (MoS2) structure and breaking its isotopic optical property are crucial for fabricating high‐performance multidimensional photodetectors. However, achieving this remains a challenge. Herein, by introducing a cavity in the channel, the strain tunable suspended MoS2 phototransistor is fabricated. By pumping the environment, a pressure difference between the environment and cavity is generated, inducing strain in the MoS2. Simulation reveals the strain can be tuned up to 0.598% by changing environment pressure. The electrical and photoelectrical properties exhibit significant tuning in response to pressure. During this experiment, the conductance of MoS2 under different pressures shows considerable differentiation between 50 and 100 kPa. As light wavelength decreases, the trend of photocurrent increasing under different pressure becomes more apparent. The differential conductance–voltage curve of different wavelengths at 10 Pa is more dispersed than that at 101 kPa. Those results demonstrate the coupling effect between light and strain. Interestingly, the symmetric photoelectrical property of MoS2 can be broken, resulting in polarization detection. At a pressure of 60 kPa, the dichroic ratio reaches 1.38, similar to intrinsic anisotropic two‐dimensional materials. This can be attributed to the breaking of symmetric structure caused by strain.

Suspended 2D Materials: A Short Review

“…Suspended 2D materials offer significant potential for a diverse range of applications due to their ultra-thin nature, high strength, high conductivity, and high transparency. One prominent application lies in electronic devices, including FETs [41,60,61], logic gates [62,63], photodetectors [64][65][66][67][68], resonators [69][70][71][72], and sensors [73][74][75][76][77][78]. For instance, Han et al demonstrated that incorporating piezoresistive properties in suspended graphene membranes enhances sensitivity and expands the temperature-sensing range in nanoelectromechanical system (NEMS) temperature sensors [129].…”

“…We offer insights into suspended configurations' experimental techniques, advantages, and limitations. The findings presented here will serve as a valuable resource for researchers aiming to harness the full potential of 2D materials in various applications, including FETs [41,60,61], logic gates [62,63], photodetectors [64][65][66][67][68], resonators [69][70][71][72], and sensors [73][74][75][76][77][78].…”