2025/09/02 by Andrew Armstrong, Armstrong, Andrew M., Evan M. Anderson +15 · 1 voice
Engineering · Physics and Astronomy · #Advanced Semiconductor Detectors and Materials #Radiation Detection and Scintillator Technologies #Semiconductor materials and interfaces
paper · doi:10.1088/1361-6641/ae1b37
openalex created_date 2025/11/04 · openalex publication_date 2025/11/04 · openalex updated_date 2026/07/30
Abstract Characterizing intrinsic defects is an essential step in evaluating materials for novel optoelectronic device applications. For photomultipliers, suppressing dark currents is critical, but a tradeoff is present between maximizing the band gap while remaining sensitive to the wavelength of interest and minimizing the incorporation of fresh defects by growing not-yet-optimized alloys. We present a series of capacitance-based measurements, including deep-level optical spectroscopy, steady-state photocapacitance, and illuminated capacitance-voltage, on photodiodes with lightly n -type Al x In y Ga 1− x − y P absorber regions. Several deep levels are identified, including one near the midgap. Although the inclusion of aluminum increases each trap density by approximately 10×, the hole capture cross-section also appears to decrease, suggesting that Shockley–Read–Hall dark currents may be suppressed. These materials may be good candidates for the development into silicon photomultiplier analogs with a wider bandgap for scintillator applications.