Unscrambling for Subgap Density-of-States in Multilayered MoS₂ Field Effect Transistors under DC Bias Stress via Optical Charge-Pumping Capacitance-Voltage Spectroscopy

Herein, we quantitatively analyze the evolution of subgap density states (DOSs) for multilayered molybdenum disulfide (m-MoS 2 ) field effect transistors (FETs) with bilayered SiN xmlns:xlink="http://www.w3.org/1999/xlink">x /SiO gate dielectrics under positive bias stress (PBS) and negative (NBS) by using optical charge-pumping capacitance-voltage spectroscopy. To decouple external gas ambient effects on device instability, hydrophobic fluoropolymers (cyclized transparent polymer; CYTOP) are employed m-MoS FETs followed evaluation subgap-DOSs in devices respective PBS (or NBS). Through extraction their deconvolution an analytical model acceptor donor)-like states, it is shown that instability closely correlated state transitions DOSs, corresponding to shallow midgap) levels monosulfur vacancy (V xmlns:xlink="http://www.w3.org/1999/xlink">S disulfur ( V xmlns:xlink="http://www.w3.org/1999/xlink">S2 )). Moreover, after PBS, initial (0) H (0)) transit toward (-1) (-1)) via electron trapping, whereas transition (+1) during NBS assessed from states. Furthermore, technology computer-aided design (TCAD) simulation based extracted DOSs properly replicates measured I-V characteristics (and without) CYTOP encapsulation. In this study, subgap-DOS characterization charge pumping validation quantitative suggest platform can be potentially beneficial in-depth understanding origins metal dichalcogenide (MX )-based FETs, where M a X chalcogenide.