New AlN Photodetector Demonstrates Linear Response to Ultra-Bright Light at High Temperatures
Researchers have demonstrated an aluminum nitride (AlN) photodetector capable of measuring very bright blue light exceeding 40 W/cm² without saturating, while maintaining accurate response at temperatures up to at least 300°C. The device exploits point defects deep within the material's bandgap at a metal-AlN Schottky junction, a mechanism enabled by careful dopant design and contact engineering. This advance could support reliable sensing in extreme environments such as industrial furnaces, nuclear reactors, and aerospace applications.
A research team has developed a sub-bandgap photodetector based on aluminum nitride (AlN), an ultra-wide-bandgap (UWBG) semiconductor, that maintains a non-saturating linear response to blue light intensities exceeding 40 W/cm²—far beyond the capabilities of conventional photodetectors, which typically saturate at low-to-moderate light levels. The device's performance stems from photoresponse mediated by deep-level point defects located energetically deep within AlN's bandgap at the metal-semiconductor Schottky junction. The authors show that engineering a narrow space charge region is critical to enabling detection of ultra-bright light and preserving measurement accuracy. Crucially, the detector also sustains undistorted linear response at elevated temperatures of at least 300°C, a regime where many conventional semiconductor devices degrade or fail. The work establishes a broader design strategy for UWBG semiconductor devices intended to operate reliably under extreme conditions. Potential application areas identified by the authors include industrial process control, thermal and nuclear power generation, and aeronautics and spaceflight. The preprint was submitted to arXiv on June 5, 2026, and has not yet undergone formal peer review.
What's missing
As a preprint, this work has not yet been peer-reviewed. The study does not report the detector's noise floor, minimum detectable signal, or spectral selectivity in detail. Long-term stability and performance under sustained radiation or thermal cycling—conditions relevant to nuclear and aerospace use—are not characterized. The upper temperature limit of 300°C is noted as a lower bound ('at least'), leaving the true operational ceiling undefined.
What different sources said
- arXiv physicsCenter
An ultra-wide-bandgap semiconductor photodetector for linear measurement of bright sub-bandgap light
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