Low-Voltage, Long-Term Stable Organic Heterojunction Transistors with Broadband Bidirectional Photoresponse for In-Sensor Vision Computing

Abstract

In-sensor vision computing enables visual sensors to perform computations during image acquisition, substantially reducing energy consumption and latency. Conventional phototransistors, however, typically exhibit unipolar photoresponse and limited logic capabilities, while silicon-based sensors are confined to the visible spectrum, leading to information loss and reduced computational accuracy. Here, we introduce an organic heterojunction transistor incorporating a HfO₂/SiO₂ stacked dielectric. This architecture simultaneously enables low-voltage operation (<5 V) and long-term stability while maintaining well-defined, gate-tunable positive and negative photoresponses. The device exhibits broadband sensitivity spanning 530–1050 nm, allowing effective multi-wavelength detection and processing. Notably, it retains over 80% of its initial responsivity after 70 days of storage, demonstrating exceptional durability. Gate-voltage modulation establishes a linear correlation between responsivity and voltage, enabling real-time in-sensor computing. Using this device, multi-wavelength image processing and classification can be performed efficiently, achieving 99.27% recognition accuracy. This work establishes a compact, low-power, and robust platform for advanced in-sensor vision computing, paving the way for miniaturized, energy-efficient, and multi-spectral imaging systems.