High-performance broadband photodetector with imaging application based on tantalum nickel selenium at room temperature

Infrared photodetectors (PDs) are widely used in fields such as military, medical, and aerospace. Traditional semiconductor materials including Si, InGaAs, and HgCdTe show high performance in a wide spectral range with the imaging function. Nevertheless, they also have limitations such as low-temperature operation, high cost, and toxicity. Fortunately, two-dimensional (2D) materials with narrow bandgaps featuring adjustable gaps, mechanical flexibility, and superior optoelectronic properties have the potential to bridge the gap between traditional materials in optoelectronic devices. However, 2D materials’ performance with respect to responsivity (Rλ) and external quantum efficiency (EQE) needs improvement. Tantalum nickel selenium (Ta2NiSe5) with a direct bandgap and high carrier mobility has prospects for broadband PD research. This study combines mechanical exfoliation and micro-nano-processing technology to prepare Ta2NiSe5 nanosheets and design a Ta2NiSe5-based PD, which has a broadband light response from 520 to 1550 nm with an Rλ value of up to 1.07 A/W. The highest EQE of the PD is 2.55, with the lowest noise equivalent power of 2.39 × 10−12 W/Hz1/2 and the highest specific detectivity (D*) of 9.3 × 108 cm Hz1/2/W. The response speed is stable with low power consumption, and the PD can perform high-resolution imaging through different liquids. Hence, Ta2NiSe5-based PDs have photoelectric properties including broadband detection, high responsiveness, and low-light detection, with a broad range of application in new optoelectronics.