Advanced Architectures and Emerging Materials for High-Operating-Temperature Infrared Photodiodes.

High-operating-temperature (HOT) mid-wavelength and long-wavelength infrared photodetectors have emerged as critical enablers for eliminating bulky cryogenic cooling systems, offering transfromative potential in developing compact, energy-efficient infrared technologies with reduced size, weight, power, and cost. Focusing on infrared photodiodes, this review first discusses the fundamental mechanisms limiting performance at elevated operating temperatures. Subsequently, the progress in conventional epitaxial semiconductors, such as HgCdTe, InAsSb, and III-V type-II superlattice is reviewed, highlighting the evolution of device architectures designed to effectively suppress dark currents and approach background-limited performance. The review then surveys recent advancements in emerging material systems for HOT infrared photodiodes, including colloidal quantum dots, 2D materials, and amorphous or polycrystalline thin films. Finally, a comparative analysis of the high-temperature performance of devices from both conventional and emerging material systems is presented to enable benchmarked evaluation, followed by an outlook on future research directions.