pBn type short-wavelength infrared photodetector with an ultralow dark current and extended wavelength based on a strained InGaAs/GaAsSb superlattice

• Published in: Optics letters Vol. 49; no. 23; p. 6769
• Main Authors: Cao, Peng, Bentley, Matthew, You, Minghui, Wei, Jiaqi, Peng, Hongling, Wang, Tiancai, Song, Chunxu, Zhuang, Qiandong, Zheng, Wanhua
• Format: Journal Article
• Language: English
• Published: United States 01.12.2024
• ISSN: 1539-4794
• DOI: 10.1364/OL.543761

An InGaAs/GaAsSb type II superlattice (T2SL) absorber is a promising alternative material for a short-wavelength infrared (SWIR) photodetector due to the largely tunable bandgap by adjusting the thickness and material composition of InGaAs and GaAsSb in each T2SL period. We demonstrate a pBn type SWIR photodetector consisting of a strained InGaAs/GaAsSb T2SL absorber and AlGaAsSb barrier. The device presents an ultralow dark current density of 1.81 × 10  A/cm and a peak responsivity of 0.38 A/W under a reverse bias of -1 V at 300 K. The detector shows a peak detectivity of 1.62 × 10 cm·Hz /W and 4.63 × 10 cm·Hz /W under a reverse bias of -1 V at 260 K and 300 K, respectively. Moreover, our photodetector demonstrates an extended 100% cutoff wavelength response up to 2.2 μm.