Broadband and Efficient Photon Harvesting of Ta 2 PdS 6 Phototransistor for Imaging and Encoding

Abstract High sensitivity and wide‐band detection capability at room temperature are the major development trends of optoelectronic devices. 2D noble‐transition‐metal chalcogenides (NTMCs), a novel class of materials, have emerged with superior optoelectronic attributes compared to conventional 2D transition‐metal dichalcogenides and zero‐bandgap semimetals. These characteristics include exceptional ultra‐high air stability, tunable bandgaps, and high photoresponsivity, positioning NTMCs as a leading material for photodiode applications. Herein, a multilayer Ta 2 PdS 6 photodetector is demonstrated, which has shown remarkable photoresponse across the 520–1550 nm spectrum, with particular effectiveness at 1550 nm, thereby underscoring its promise for optical communication. Moreover, integrating a tunable periodic logarithmic interdigital microstructure has facilitated the extraction of hot carriers from low‐energy photons, enabling sub‐bandgap terahertz photoconversion. This enabled room‐temperature detection and imaging at 0.04–0.30 THz, with the responsivity of 49.6 V W −1 (0.12 THz) and 7.4 V W −1 (0.30 THz) at zero bias voltage, and response time faster than 4 µs. Significantly, the Ta 2 PdS 6 photodetector showcased in this study exhibits exceptional stability, a critical attribute for the practical deployment of optoelectronic devices. This work highlights the significant potential of NTMCs in advancing wide‐band optoelectronics, laying a solid groundwork for the evolution of future technological innovations in the field.