Fig. 6: Gain and k versus Hg1–xCdxTe bandgap energy.
From: Infrared avalanche photodiodes from bulk to 2D materials
a the crossover between e-APD and h-APD. The crossover at Eg ≈ 0.65 eV corresponds to the λc = 1.9 μm for 300 K46. Hole-initiated avalanche HgCdTe photodiode: b detector profile, c energy band structure, d hole-initiated multiplication process energy band structure. The multiplication layer bandgap energy is adjusted to the resonance condition where the bandgap and the split-off valence band energy and the top of the heavy-hole valence band energy difference are equal. Electron-initiated avalanche HgCdTe photodiode: e diagram of electron-initiated avalanche process for HgCdTe-based high-density vertically integrated photodiode (HDVIP) structure (n-type central region and p-type material around), f electron avalanche mechanism, and g relative spectral response for 5.1 μm cut-off wavelength HgCdTe HDVIP at T = 80 K
