Controlled growth of Large-Area 2D palladium diselenide with tunable electronic properties for optoelectronics and artificial synapses devices

Two-dimensional palladium selenide (PdSe 2 ) is a promising material for next-generation optoelectronic and neuromorphic applications due to its high carrier mobility, tunable bandgap, and excellent air stability. In this work, we report a scalable liquid-phase-precursor-assisted chemical vapor deposition (CVD) strategy for the large-scale growth of high-uniformity, thickness-tunable 2D PdSe 2 films. By precisely controlling precursor concentration and spin-coating speed, we achieve fine modulation of electronic properties including bandgap, work function, and band alignment. The as-grown films exhibit excellent device performance across multiple platforms: arrayed field-effect transistors (FETs) demonstrate intrinsic bipolar transport with electron mobilities up to 30 cm 2 ·V −1 ·s −1 and stable on/off ratios; broadband photodetectors show high responsivity (up to 102.2 A·W −1 ) and detectivity (∼10 9 Jones); and flexible artificial synapses deliver exceptional linearity ( R 2  = 0.995), mechanical robustness, and up to 83.26 % recognition accuracy on the MNIST dataset. This work offers a unified approach that links growth-process engineering with functional device performance, paving the way for large-scale applications of 2D PdSe 2 in neuromorphic and flexible optoelectronics.