Platinum Disulfide (PtS2) and Silicon Pyramids: Efficient 2D/3D Heterojunctions Tunneling and Breakdown Diodes

Abstract: The p-n junction constructed from the group-10 TMDCs, or namely, transition metal dichalcogenides with an intrinsic layered structure, is not considerably reported. This study presents a mechanical exfoliation-based technique to prepare PtS2 pyramids Si p-n junctions for an investigation of the tunneling and breakdown diodes. the demonstrated p-n diode exhibited a high rectifying performance reaching a rectification ration (If/Ir) to 7.2 *10^4 at zero gate bias with an ideality factor of 1.5. The zener tunneling was observed at a low reverse bias region of breakdown voltage (from -6 to -1V) at various temperatures (50 to 300K) and it was a negative coefficient of temperature. Conversely, for the greater breakdown voltage regime (-15 to -11 V), the breakdown voltage increased with the increased temperature (150 to 300 K), indicating a positive coefficient of temperature. Therefore, this phenomenon was attributed to the avalanche breakdown. The p-n junctions displayed photovoltaic characteristics under the illumination of visible light (500 nm), such as high responsivity (Rph) and photo gain (G) of 11.88 A/W, and 67.10, respectively. The maximum values for both the open-circuit voltage (VOC) and the short-circuit current (ISC) were observed to be 4.5 V, and 10 uA, respectively, at an input intensity of light 70.32 mW/cm2. The outcome of this study suggest PtS2/pyramids Si p-n junctions may be employed in numerous optoelectronics including photovoltaic cells, Zener tunneling diodes, avalanche breakdown diodes and photodetectors.