High-Performance Ultraviolet to Near-Infrared Antiambipolar Photodetectors Based on 1D CdS_<i>x</i>Se_1–<i>x</i>/2D Te Heterojunction

Antiambipolar heterojunctions are regarded as a revolutionary technology in the fields of electronics and optoelectronics, enabling the switch between positive and negative transconductance within a single device, which is crucial for diverse logic circuit applications. This study pioneers a mixed-dimensional photodetector featuring antiambipolar properties, facilitated by the van der Waals integration of one-dimensional CdS_<i>x</i>Se_1-<i>x</i> nanowires and two-dimensional Te nanosheets. This antiambipolar device enables flexible control over carrier transport via gate voltage, thus paving new paths for future optoelectronic devices. Furthermore, by precisely managing the stoichiometry of the ternary alloy CdS_<i>x</i>Se_1-<i>x</i> nanowires, fine-tuning of the nanowire band structure is achieved. This allows for customizable heterojunction band alignment (Type I and Type II), enabling adjustable band alignment. Through sophisticated band engineering, optimal Type II band alignment is achieved at the CdS_<i>x</i>Se_1-<i>x</i>/Te interface, significantly enhancing the device's photoelectric conversion efficiency through the synergistic effect of different dimensional materials. Exhibiting outstanding photoresponse across a broad spectral range from ultraviolet to near-infrared, especially under 450 nm illumination, the CdS_<i>x</i>Se_1-<i>x</i>/Te heterojunction photodetector demonstrates superior performance, including an impressive responsivity of 284 A W^-¹, a high detectivity of 1.07 × 10¹⁷ Jones, an elevated external quantum efficiency of 7.83 × 10⁴ %, and a swift response time of 11 μs. Ultimately, this customizable antiambipolar photodetector lays a solid foundation for the advancement of next-generation optoelectronic technologies.