nBn mid-wavelength infrared photodetectors based on bulk InGaAsSb absorbers

Cao, Peng and Wei, JiaQi and Bentley, Matthew and Davison, Nicholas and Hu, Yidan and You, Minghui and Peng, Hongling and Wang, Tiancai and Zhuang, Qiandong and Zheng, Wanhua (2025) nBn mid-wavelength infrared photodetectors based on bulk InGaAsSb absorbers. Optical Materials Express, 15 (4). pp. 717-723. ISSN 2159-3930

Text (nBn_mid-wavelength_infrared_photodetectors_based_on_bulk_InGaAsSb_absorber-clean_version)
nBn_mid-wavelength_infrared_photodetectors_based_on_bulk_InGaAsSb_absorber-clean_version.pdf
Available under License Creative Commons Attribution.
Download (2MB)

Abstract

In this paper, we demonstrate an nBn mid-wavelength infrared (MWIR) photodetector with a 100% cutoff wavelength over 4.0 µm based on a high-In composition InGaAsSb absorber on GaSb substrate. A thin AlGaAsSb layer is exploited as the barrier layer to suppress the generation-recombination (G-R) current. Both structural and optical properties of the grown InGaAsSb epilayer are investigated by high-resolution X-ray diffraction (HRXRD) and photoluminescence (PL) measurement. Low dark current density down to 9.9 × 10−5 A/cm2 and 6.5 × 10−2 A/cm2 are obtained at −500 mV under 77 K and 300 K, respectively. Moreover, respective peak responsivity of 0.64 A/W and 0.10 A/W at 2.67 µm are achieved at −500 mV under 77 K and 160 K. These correspond to a peak specific detectivity of 1.06 × 1011 cm·Hz1/2/W and 4.23 × 109 cm·Hz1/2/W, respectively.