GaSb/GaAlAsSb Heterostructure Photodiodes for the Near-IR Spectral Range

摘要

GaSb/GaAlAsSb uncooled photodiodes for the 1 . 1–1 . 85 μm spectral range are fabricated and studied. A unique method for the growth of GaSb from lead solution-melts makes it possible to obtain a low carrier concentration in the active region: n = 2 × 10_(15)cm_(–3). The capacitance of the photodiodes is 70–110?pF for a sensitive -area diameter of 300 μm and 150–250 pF for a diameter of 500 μm. The photodiodes are characterized by a high (for GaSb devices) spectral sensitivity S ~(λ)= 0 . 95 A/W at the maximum, a relatively low reverse dark current density j = (4–9) × 10_(–3)A/cm_(2)at U ~(rev)= 1 . 0–2 . 0 V, and high-speed performance (response time 5–10 ns).