Strain affected electronic properties of bilayer tungsten disulfide

ACS Appl. Electron. Mater.

et al. 2020

Flexible electronics have brought considerable benefits to healthcare advancement by their powerful functions of mimicking human skin to quantitatively transform external stimuli into electronic signals with corresponding feedback instructions. Though the energy consumption also has been significantly reduced by self-powered units such as a triboelectric nanogenerator (TENG) and a piezoelectric nanogenerator (PENG), these generators cannot precisely reflect the movement lasting time with high precision. Traditional capacitive and resistive sensors can measure the duration time of external stimuli, but they fail to be self-powered. Here, a self-powered sensor is presented based on an Al/PPy/Au generator with the ability to record the magnitude and duration time of movement without sacrificing the high stretchability. The generator rendered a direct current output accessible through a Schottky contact between polypyrrole (PPy) and an aluminum electrode and a long-time-lasting output through the mechanical relaxation phenomenon of PPy. Based on this mechanism, the sensor is capable of sensing quantitative deformation and action duration. Furthermore, the sensor can recognize pentatonic scales and movement of fingers, shedding light on low-power-consuming flexible electronics and exhibiting promising applications in versatile sensory systems, intelligent medical diagnostic systems, and human–machine interactive interfaces.

Section: Results and Discussionmentioning

confidence: 99%

Stretchable Self-Powered Generator for Multiple Functional Detection

Meng

ACS Appl. Electron. Mater.

et al. 2020

“…It should be noted that at even larger compressive strain (ε > −3%), the band gap can be further decreased. [13][14][15]17) The effective masses is extracted along the K-Γ and K-M directions by fitting to the parabolic band. The effective mass along the K-Γ and K-M directions are almost the same.…”

Section: Resultsmentioning

confidence: 99%

“…Biaxial strain is applied to monolayer MoS 2 in the rhombus supercell structure by altering the lattice constants along the x-and y-directions. [13][14][15][16][17] The double gate FET structure is used, as shown in Fig. 1(c), for better gate controllability.…”

Section: Device Structure and Simulation Methodsmentioning

confidence: 99%

Strain effects on monolayer MoS₂field effect transistors

Zeng

Chang

et al. 2015

Jpn. J. Appl. Phys.

In this work, the strain effect on monolayer MoS 2 field effect transistors is investigated by density functional (DFT) calculation and quantum transport simulation. DFT calculation reveals that the tensile strain decreases the effective mass, while compressive strain increases the effective mass. However, ballistic quantum transport simulation shows that a smaller effective mass does not always result in better performance for a 5 nm gate length transistor. This is because for field effect transistors in the ultimate scaling region, the suppression of off-state tunneling current is the greatest concern in device design. The effect of scattering is considered by a simple approach and is shown to have a stronger impact on the intrinsic delay for the 10 nm gate length transistor.

“…The directcurrent output origins from the mechanical-induced interfacial charge accumulation and the energy-band bending. As a result, the Schottky barrier between the conductive polymer and the metal that forms the Schottky contact reduces and drives the movement of electrons from conductive polymers to the other metal electrodes [36][37][38][39][40] .…”

Section: The Output Properties Of the Polymer-metal-schottky-contact-based Direct-current Generatorsmentioning

confidence: 99%

Direct-current generators based on conductive polymers for self-powered flexible devices

Meng

et al. 2021

Preprint

Direct-current generators, especially those based on the Schottky contacts between conductive polymers and metal electrodes, are efficient in converting mechanical stimuli into electrical energy. In contrast to triboelectric and piezoelectric generators, direct-current generators readily produce direct-current outputs and high currents that are crucial for integrating multiple energy-harvesting units in large scale and driving some types of devices. We are focusing on the relationship between Schottky barrier height and performance, systematically investigating the effects of various conductive polymers and electrodes on the outputs by both theoretical simulation and experiments. Tailoring the Schottky barrier height between conductive polymers and metal electrodes is demonstrated a significant approach to design the new DC generators. The preparation method of electrochemical deposition endows the generators flexibility, the linear relationship of current/voltage output vs. strain applied on the generators, combined with the large outputs offer advantages for the generator to work as flexible sensors. Furthermore, a mechanosensation-active matrix array based on direct-current generator for the strain monitoring demonstrated its promising prospects in flexible electronics. The direct-current generators with improved performance could serve as a stream new blood for versatile sensory systems and human-machine interactive interfaces.