Heterointerface‐Functionalized Photoelectric Response of Metal‐Oxide Schottky Photodiode for Intelligent Fire Detection

Ultraviolet photodetectors (UV‐PDs) based on wide‐bandgap oxide semiconductors (OSs) hold broad prospects in scientific, civil, and especially fire alarm applications. However, the hotly pursued flexible and hetero‐integration capabilities are hindered by the high processing temperature of mainstream Ga 2 O 3 UV‐PDs, while the selective UV detection capability of low‐temperature OS (LT‐OS) is undermined by the pronounced contradictory effects of abundant native defects on electric and optoelectrical properties. Herein, a heterointerface‐functionalized Schottky photodiode (HF‐SPD) is proposed to realize high‐performance LT‐OS UV‐PD. Due to the sophistically modulated Schottky contact and defect distribution, ultralow dark current and remarkable photoresponse are simultaneously achieved in In 2 O 3 HF‐SPDs. Under the typical 360‐nm UV illumination, the responsivity ( R ) and detectivity ( D * ) respectively reach 27.75 A W −1 and 2.036 × 10 13 Jones, enabling the early‐fire‐warning capability. Moreover, the HF‐SPD possesses unique wavelength selectivity and bias‐tunable photoelectrical characteristics. By feeding such multidimensional feature data into the multi‐layer perceptron (MLP) neural network, the pattern recognition of the spectrum delivers a remarkable accuracy of 99.94%, ensuring the precise identification of combustion materials. Such an intelligent fire warning system demonstrates the prospects of algorithm‐boosted LT‐OS HF‐SPDs in ubiquitous intelligent systems, such as wearable photodetection and in‐sensor computing (ISC) devices.