Self‐Powered Infrared‐Detectable BP/Ta ₂ NiS ₅ Heterojunction and Its Application in Energy‐Efficient Optoelectronic Synapses

The development of energy-efficient and high-performance optoelectronic devices is crucial for the advancement of modern optoelectronic and microelectronic systems. Although the self-powered devices and optoelectronic synapses based on 2D heterojunction show great application prospects, the high energy consumption and infrared band detection of self-powered optoelectronic synapses are still an urgent problem to be solved. In this report, a BP/Ta₂NiS₅ heterojunction is constructed to achieve infrared detection by leveraging differences in Fermi energy levels. This heterojunction exhibits a high specific detectivity of 6.57 × 10¹⁰, 2.6 × 10¹⁰, and 1.12 × 10¹⁰ Jones and responsivity of 20, 10.6, and 5.9 mA W^-1 for 1064, 1550, and 2200 nm infrared light at 0 bias voltage, respectively. In addition, under the 2200 nm light, by applying an ultra-low bias voltage of 800 µV, the heterojunction exhibits ultra-low power and energy consumption of 28.8 pW and 0.64 pJ, successfully simulates a variety of synaptic behaviors under infrared light, and demonstrates its image perception and image memory capabilities. These findings position the BP/Ta₂NiS₅ heterojunction as an ideal candidate for a multifunctional optoelectronic device crucial for advanced photodetection, neuromorphic computing, and artificial intelligence.