The Need

Solar-blind UV detection (200–280 nm) is essential across defense, fire detection, secure optical communications, environmental monitoring, and space applications. Existing solutions — photomultiplier tubes and filtered silicon photodetectors — are bulky, fragile, require high operating voltages, and are poorly suited for harsh or field-deployable environments. Solid-state ultra-wide bandgap photodetectors offer a compelling alternative, but leading designs suffer from poor UV-to-visible selectivity driven by parasitic sub-bandgap photocurrent, limiting their utility in real-world detection scenarios.

The Technology

OSU engineers have developed a novel solid-state solar-blind photodetector architecture that substantially eliminates the primary source of sub-bandgap photocurrent in vertical Schottky-type designs. By incorporating a thin engineered interlayer at the metal-semiconductor junction, the device suppresses internal photoemission from the metal contact — the dominant mechanism that degrades UV-visible selectivity in conventional designs. The result is a photodetector with dramatically improved spectral selectivity and noise performance while preserving strong UV responsivity.

Commercial Applications

• Defense & national security: Missile plume and UV-threat detection in high-background solar environments
• Fire detection: Industrial and infrastructure flame sensing requiring false-alarm-resistant UV detection
• Secure optical communications: UV-band free-space communication systems requiring high spectral discrimination
• Environmental & atmospheric monitoring: Deep-UV sensing for ozone, photochemical, and space-based applications

Benefits/Advantages

• Dramatically improved UV-visible rejection ratio: Selectivity improved by over 9,000× compared to conventional Schottky photodetectors
• Ultra-low dark current: Noise floor reduced by approximately four orders of magnitude relative to standard Schottky designs
• Filter-free, solid-state architecture: Inherent solar-blindness from the wide bandgap semiconductor eliminates the need for optical filters
• Maintained UV responsivity: Spectral selectivity gains are achieved without sacrificing detection efficiency at target UV wavelengths