Effects of carrier injection profile on low noise thin Al₀₈₅Ga₀₁₅As₀₅₆Sb₀₄₄ avalanche photodiodes

Abstract

5787318).

Extremely low-noise avalanche photodiodes based on AlAs0.56Sb0.44

“…One problem encountered with AlAsSb is that the material system is prone to oxidizing very easily when exposed to air, consequently passivation of the devices is necessary. Excess noise measurements on thin AlGaAsSb (Al=85%) p-i-n diodes showed that a k = 0.1 could be achieved with a 87 nm avalanching width and that this improved to k = 0.05 when the width increased to 170 nm [33]. A much thicker structure may well give similar k values to that seen in AlAsSb, but with the added advantage that the AlGaAsSb material system should be more stable.…”

Evolution of Low-Noise Avalanche Photodetectors

“…AlGaAsSb/InGaAs SACM APDs have been developed with multiplication and absorption layer thicknesses of 100 nm and 300 nm, respectively. These APDs exhibited keff of 0.05 to 0.08 89 and gain bandwidth product ~4 20 GHz. 90 Aside from InAs, which has demonstrated > 500 GHz, this is the highest gain-bandwidth product reported for any APD.…”

AlGaAsSb Avalanche Photodiodes

“…Using a 543 nm wavelength laser as excitation source, which did not achieve pure electron injection, the best data corresponded to an effective ionization coefficient ratio, k eff , of 0.1. Recently the excess noise measurements were improved in [8], which used a 420 nm wavelength excitation source to achieve pure electron and pure hole injection for p-i-n and n-ip diodes, respectively. Data of Al 0.85 Ga 0.15 As 0.56 Sb 0.44 p-i-n diodes from [8] corresponded to k eff as low as 0.05-0.08.…”

“…Recently the excess noise measurements were improved in [8], which used a 420 nm wavelength excitation source to achieve pure electron and pure hole injection for p-i-n and n-ip diodes, respectively. Data of Al 0.85 Ga 0.15 As 0.56 Sb 0.44 p-i-n diodes from [8] corresponded to k eff as low as 0.05-0.08. Both works found electron injection to be preferable for achieving the lowest possible excess noise characteristics, hence electrons have higher ionization coefficient than holes.…”

“…Fig.2. Excess noise factor versus avalanche gain characteristics measured from two Al0.85Ga0.15As0.56Sb0.44 p-i-n didoes (87 and 170 nm avalanche layer thickness), using different excitation wavelengths (symbols)[8]. Fittings (grey lines) indicate the data correspond to keff of 0.1 (top) and 0.05-0.08 (bottom).…”