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

Zongheng Xie,Xinbo Zou,Baile Chen,Zhuo Deng

doi:10.1109/lpt.2020.3008853

Abstract

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 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.26\times 10 ^{\mathbf {-5}}$ </tex-math></inline-formula> A/cm 2 for In 0.53 Ga 0.47 As sub-detector under −0.1 V bias and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3.78\times 10 ^{\mathbf {-2}}$ </tex-math></inline-formula> 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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.63\times 10 ^{\mathbf {11}}$ </tex-math></inline-formula> cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula> Hz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\mathbf {1/2}}$ </tex-math></inline-formula> /W at 1640 nm for NIR sub-detector and 0.22 A/W and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.96\times 10 ^{\mathbf {9}}$ </tex-math></inline-formula> cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula> Hz 1/2 /W at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2~\mu \text{m}$ </tex-math></inline-formula> 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.

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