High operating temperature nBn detector with monolithically integrated microlens

摘要

We demonstrate an InAsSb nBn detector monolithically integrated with a microlens fabricated on the back side of the detector. The increase in the optical collection area of the detector resulted in a five-fold enhancement of the responsivity to R_p = 5.5 A/W. The responsivity increases further to R_p = 8.5 AAV with an antireflection coating. These 4.5 μm cut-off wavelength antireflection coated detectors with microlenses exhibited a detectivity of D* (λ)= 2.7 × 10~(10) cmHz~(0.5)/W at T=250K, which can be reached easily with a single-stage thermoelectric cooler or with a passive radiator in the space environment. This represents a 25 K increase in the operating temperature of these devices compared to the uncoated detectors without an integrated microlens.