Highly Responsive Flexible Photodetectors Based on MOVPE Grown Uniform Few-Layer MoS₂

Abstract

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) are seen as promising candidates for flexible electronic and optoelectronic devices due to their high tensile strength and favorable optical properties. Molybdenum disulfide (MoS2) is a benchmark material for TMDCs, which has already been studied extensively. Here, we report on highly responsive flexible few-layer MoS2 photodetectors based on MoS2 synthesized uniformly for full coverage of 2 in. sapphire wafers using metalorganic vapor-phase epitaxy (MOVPE). Device performance is studied by electro-optical characterization. Electrostatic gating allows tuning both the responsivity between 150 and 920 A/W and the specific detectivity between almost 1012 and 1010 Jones. The measured spectrally resolved responsivities of the detectors suggest applications in the blue-light range, with opportunities for fine-tuning the most sensitive wavelength through gating, as shown through optical simulations. Finally, the flexible devices were bent to demonstrate their suitability for flexible electronics in fields of future Internet of Things and medical devices.