High-Performance Ultra-Broadband Photodetector Based on Fe₃O₄/CrSiTe₃ Heterostructures

Photodetectors based on advanced materials with a broad spectral photoresponse, high sensitivity, huge integration ability, room-temperature operation, and stable environmental stability are highly desired for diversified applications of imaging, sensing, and communication. Herein, a high-performance ultra-broadband photodetector based on an ultrathin two-dimensional (2D) Fe₃O₄ nanoflake heterostructure with high sensitivity was designed. The photodetector response light was from visible 405 nm to long-wave infrared (LWIR) 10.6 μm in ambient air. The competitive performances, including a high photoresponsivity (<i>R</i>) of 182.8 A W^-1, fast speed with the rise time τ_r = 8.8 μs, and decay time τ_d = 4.1 μs, were demonstrated in the visible range. Notably, the device exhibits an excellent uncooled LWIR detection ability, with a high <i>R</i> of 1.4 A W^-1 realized at a 1.5 V bias. In the full spectral range, the noise equivalent power is lower than 0.79 pW Hz^-1/2, and specific detectivity (<i>D</i>*) is higher than 4.9 × 10⁸ cm Hz^1/2 W^-1 in ambient air. This work provides alternative ultrathin 2D materials for future infrared optoelectronic devices.