High-temperature mid-wavelength infrared avalanche photodiode with modified fully-depleted absorption and multiplication region

Mid-wavelength infrared (MWIR) avalanche photodiodes (APD) are extensively employed in high-precision detection and thermal imaging in complex context. However, conventional MWIR APD’s detection typically requires low-temperature operation to relieve signal-to-noise limitations imposed by narrow bandgap materials. Here, to address this challenge, we present the high-temperature-operating MWIR avalanche photodiodes with a modified fully-depleted absorption, multiplication region (MFDAM) to suppress the high dark current. At 80 K, the proposed APD achieves comparable gain-normalized dark current density (GNDCD) still <6 × 10 ⁻¹⁰ A/cm ² at gain <20. At 160 K, the GNDCD preserves consistently below 2 × 10 ⁻⁶ A/cm ² for gain values less than 189, while the excess noise holds below 1.4 and the noise equivalent power is <7.2 × 10 ⁻¹⁶ W/Hz ^1/2 of 3.5 μ m. The device is also validated for imaging targets up to 200 km away at a gain of <10. These results enable the MFDAM APDs to be promising and desirable for future high-temperature-operating MWIR detection applications.