High-Performance Van der Waals Photodetectors Based on Metal Nanoparticles-Enabled Local Surface Plasmon Resonance Effect

Two-dimensional semiconductor materials featured with significant advantages in high surface-volume ratio and optoelectronic interactions and broad-spectrum make them promising in high-responsivity photodetectors. In this work, we propose a universal methodology for improving the optoelectronic performance of two-dimensional photodetectors by integrating metal nanoparticles onto the surface of TMDs films. Through systematic characterizations involving COMSOL finite element simulations, surface morphology, and spectral analysis, the optoelectronic performance enhancement mechanism of the device design should be contributed to the metal nanoparticle-enabled localized surface plasmon resonance (LSPR) effect. The LSPR-induced local electric field can accelerate the separation of photogenerated electron-hole pairs at the semiconductor channel surface and significantly increase photocurrent. Moreover, LSPR effect enables an enhanced light-semiconductor interaction behavior and leads to an improved light absorption efficiency. Such the synergy of the structural design endows our In-covered InSe photodetectors with high absorption of visible light at 650 nm, an exceptional responsivity of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1.23\times 10^{4}\ \mathrm{A}/\mathrm{W}$</tex>, and a fast response time of 9.8/8.7 μs. This design provides a robust strategy for designing and fabricating high-performance photodetectors.