Color-selective or wavelength-tunable capability is a crucial feature for two-dimensional (2-D) semiconducting material-based image sensor applications. Here, we report on flexible and wavelength-selective molybdenum disulfide (MoS2) phototransistors using monolithically integrated transmission Fabry-Perot (F-P) cavity filters. The fabricated multilayer MoS2 phototransistors on a polyarylate substrate exhibit decent electrical characteristics (μFE > 64.4 cm2/Vs, on/off ratio > 106), and the integrated F-P filters, being able to cover whole visible spectrum, successfully modulate the spectral response characteristics of MoS2 phototransistors from ~495 nm (blue) to ~590 nm (amber). Furthermore, power dependence of both responsivity and specific detectivity shows similar trend with other reports, dominated by the photogating effect. When combined with large-area monolayer MoS2 for optical property enhancement and array processing, our results can be further developed into ultra-thin flexible photodetectors for wearables, conformable image sensor, and other optoelectronic applications.

Enhancement-mode multilayer molybdenum disulfide (MoS2) field-effect transistors (FETs), which are an immensely important component toward low-power electronics based on a two-dimensional layered semiconductor, are demonstrated using the fluoropolymer CYTOP as a gate dielectric. The fabricated devices exhibit threshold voltage (VTH) of ∼5.7 V with field-effect mobility (μFE) of up to 82.3 cm2/V s, and the characteristics are compared with the depletion-mode characteristics of MoS2 FETs with the cross-linked Poly(4-vinylphenol) gate dielectric (VTH ∼ −7.8 V). UV photoelectron spectroscopy analysis indicates that increased surface potential due to the surface dipole effect of the fluorine group influences the positive VTH shift.

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So far most of MoS2‐based devices have been demonstrated on oxide gate dielectrics (e.g., SiO2, Al2O3, HfO2, etc) deposited by vacuum process or on polymer gate dielectrics. In this study, we report electrical characteristics of multilayer MoS2 transistors fabricated on solution‐processed high‐k AlOx gate dielectric via deep ultraviolet (DUV) activation in combination with rapid thermal annealing process at 250 °C. The solution‐processed AlOx sol–gel film exhibited low leakage current of about 1.49 μA cm−2 at 1 MV cm−1 and a relative dielectric constant (k) of ∼6.1 at 1 kHz. The fabricated MoS2‐FETs exhibit median field‐effect mobility of ∼23.3 cm2 V−1s−1, threshold voltage of ∼ 0.79 V, subthreshold slope of ∼0.30 V dec−1, and on/off current ratio of ∼107. The electrical performance can be further improved by optimizing the AlOx sol–gel film as well as the device structure, and the result implies that the solution‐processed high‐k AlOx is promising for TMDC–based device applications.