High-performance tungsten disulfide (WS₂) point-contact Schottky diodes for radio wave detection and efficient energy harvesting applications

Abstract

We present a novel dry sulfurization method for the controlled growth of tungsten disulfide (WS2) on ultra-sharp tungsten tips, utilizing ohmic heating induced by direct current (DC) voltage application. This approach enables the formation of multilayer WS2 structures at the sub-micron scale. The sulfurized tips were comprehensively characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and micro-Raman spectroscopy to confirm surface morphology and elemental composition. WS2/aluminum point-contact Schottky diodes fabricated via this method exhibited excellent electrical performance, with current-voltage (I-V) measurements revealing a high forward-to-reverse current ratio of 412 and an ultrafast reverse recovery time of 21.75 +/- 0.05 ns. Unlike conventional silicon PN junction rectifiers, which suffer from prolonged reverse conduction due to carrier recombination, our devices demonstrate rapid switching behavior comparable to commercial ultrafast diodes such as the 1N60. This makes them highly suitable for radiofrequency (RF) energy harvesting applications. Dynamic response testing confirmed effective signal detection at 530 kHz, while rectification assessments demonstrated energy harvesting capabilities, achieving an output power of 25 mu W under RF excitation. These results highlight the potential of WS2-based diodes to reduce reliance on batteries, offering a sustainable and environmentally friendly alternative for powering low-power electronic devices. Our findings underscore the promise of WS2-based point-contact Schottky diodes in high-frequency energy harvesting and RFID applications, paving the way for efficient, battery-free power solutions in nextgeneration Internet of Things (IoT) technologies.