InP-Based Near Infrared/Extended-Short Wave Infrared Dual-Band Photodetector

In this paper, InP based near infrared (NIR) /extended-short wave infrared (eSWIR) dual-band photodetector with In 0. 53 Ga 0. 47 As and In 0. 53 Ga 0. 47 As/GaAs 0. 5 Sb 0. 5 type-II superlattice (T2SL) back-to-back n-i-p/p-i-n structures is demonstrated. Monolithic growth of NIR/eSWIR dual-band photodetector on InP substrate enjoys the benefit of the lattice matched property of InP/InGaAs/GaAsSb material system. Low optical crosstalk (below −10 dB) between the two sub-detector is achieved for wavelength range out of 1690–1750 nm. At room temperature, the device exhibits a dark current density of 1. 26 10 ^ {-5} A/cm 2 for In 0. 53 Ga 0. 47 As sub-detector under −0. 1 V bias and 3. 78 10 ^ {-2} A/cm 2 for In 0. 53 Ga 0. 47 As/GaAs 0. 5 Sb 0. 5 sub-detector under −1 V bias. The corresponding responsivity and specific detectivity are 0. 57 A/W and 2. 63 10 ^ {11} cm Hz ^ {1/2} /W at 1640 nm for NIR sub-detector and 0. 22 A/W and 1. 96 10 ^ {9} cm Hz 1/2 /W at 2~ m for eSWIR sub-detector, respectively. The characterization results show the potential for monolithically growing dual-band SWIR photodetector on InP substrate with low dark current density for SWIR applications.