Researchers from the University of Science and Technology of China and McGill University have developed a revolutionary diode capable of performing three distinct functions within a single component. Published in Nature Electronics in 2026, the study introduces a multifunctional p–n diode that integrates photosensing, data processing, and memory storage without requiring additional circuitry. This innovation could significantly reduce the size and energy consumption of future electronic systems. Traditional p–n diodes, which are fundamental to electronics, allow current to flow in only one direction but typically serve a single purpose. Achieving complex tasks like computation or data storage usually requires connecting multiple separate components, which increases hardware complexity and device footprint. The new device overcomes these limitations through a process known as band-structure engineering. The team constructed the diode using vertically grown nanowires composed of three semiconductor materials: p-type gallium nitride (GaN), n-type aluminum gallium nitride (AlGAN), and n-type GaN. By arranging these materials on a silicon substrate, they created a specific configuration where the AlGAN layer acts as a barrier with a larger bandgap than the surrounding layers. This barrier traps electrons to form a reservoir, enabling precise control over charge trapping and release processes that go beyond standard diode operation. Testing results demonstrated the diode's remarkable versatility. The device exhibited bias-tunable photosensing behavior with a high responsivity of 10.45 milliamps per watt. Furthermore, it mimicked biological synapses with a paired-pulse facilitation ratio of up to 122%, allowing it to process signals in a manner similar to the human brain. The diode also functioned as a memory unit, capable of maintaining eight linear states for data storage. In practical application, the researchers assembled an array of these three-in-one diodes to create a compact image sensor. This prototype successfully performed image collection, denoising, and classification simultaneously without needing separate processing chips. The integrated design offers a pathway toward miniaturized electronics that are both smaller and more energy-efficient than current technologies. Lead authors Yuanmin Luo and Huabin Yu noted that this approach simplifies hardware requirements by merging sensing and computing functions. They believe the design could inspire the creation of similar nanowire-based devices tailored for specific real-world applications. As electronics continue to demand greater efficiency and smaller form factors, this trifunctional diode represents a significant step forward in semiconductor technology, potentially redefining how image sensors and other devices are constructed in the future.