Multilayer Transition Metal Dichalcogenide Photodetectors: Systematic Performance Enhancement through Complementary Engineering Strategies

Two-dimensional transition metal dichalcogenides (TMDs) are promising candidates for next-generation optoelectronics; however, their multilayer configurations face fundamental performance limitations from indirect bandgap transitions that reduce radiative recombination and external quantum efficiency compared to monolayer systems. This spotlight article demonstrates four complementary engineering strategies, viz., intrinsic material optimization, interfacial chemical modification, physical architectural design, and structural engineering, that systematically overcome these limitations through integrated approaches. Intrinsic material engineering transforms typically detrimental defects into performance-enhancing features, achieving record photoresponsivity of 119.16 A/W–1 in bilayer MoS2 through controlled photogating mechanisms while enabling uniform 8 × 8 active-pixel arrays suitable for large-area applications. Interfacial chemical engineering introduces adaptive functionality through perovskite–MoS2 hybrids that exploit light-induced halide segregation for dynamic responsivity modulation, achieving biological-like sensory adaptation with 96.65% recovery capability and establishing stimulus-responsive photodetection beyond conventional static sensing. Physical engineering resolves the fundamental trade-off between enhancement and signal integrity through electrically self-isolated C8-BTBT/WSe2 architectures, achieving 1294% photosensitivity improvement under UV illumination while preserving the dark current stability essential for high signal-to-noise ratio applications. Structural engineering demonstrates mechanically tunable optical gain through reconfigurable aluminum mirrors, achieving 113% photocurrent enhancement (4.0 to 8.5 μA) via concave focusing effects that transform device flexibility from a design constraint into a performance advantage. These synergistic strategies collectively transcend the fundamental responsivity–transport trade-offs of multilayer TMDs. They establish integrated design principles for next-generation photodetectors that combine exceptional sensitivity with adaptive functionality, mechanical tunability, and manufacturing scalability. These advances enable applications ranging from flexible imaging systems to neuromorphic computing and augmented reality platforms.