High Operating Temperature InAs/GaSb Superlattice Based Mid Wavelength Infrared Photodetectors Grown by MOCVD

He Zhu,Yong Huang,Jiafeng Liu,Zhen Liu,Meng Li,Hong Zhu,Yunlong Huai

doi:10.3390/photonics8120564

Abstract

High operating temperature mid-wavelength InAs/GaSb superlattice infrared photodetectors with a single heterojunction structure grown by metal–organic chemical vapor deposition are reported. By inserting a fully-depleted wider-gap barrier layer between the absorber and the p-contact, “diffusion-limited” behavior has been achieved for the heterojunction “PNn” device, in contrast to the conventional pin homojunction device. The PNn device with a 50% cutoff wavelength of 4.5 μm exhibited a dark current of 2.05 × 10−4 A/cm2 and a peak specific detectivity of 1.28 × 1011 cm·Hz·W−1 at 150 K and a reverse bias of −0.1 V.

Highlights

Mid-wavelength infrared (MWIR) (3–5 μm) detectors are desired for a variety of civilian and military applications such as industrial process monitoring, satellite reconnaissance, and night vision
One critical requirement of the MWIR detectors is the capability of high operating temperature (HOT) operation [1], which reduces the burden of cryogenic cooling significantly and leads to a reduction in size and total cost of the detector system [2]
The most important factor affecting the performance of the MWIR detectors at high operating temperature is the dark current, which increases dramatically as the temperature rises and leads to a high noise level

Summary

Introduction

Mid-wavelength infrared (MWIR) (3–5 μm) detectors are desired for a variety of civilian and military applications such as industrial process monitoring, satellite reconnaissance, and night vision. The T2SLs with their high design flexibility of band structure inject considerable vitality into the development of the barrier detectors and have motivated various heterostructures, such as the PπMn structure [7,8], pMp structure [9], nBn structure [10,11], and pBn structure [12]. These structures are usually sophisticated and require a precise control of the thickness and composition. 1(R.208A×) o1f051410c.1m2·Ω√·Hcmz·2W, a−q1 uaat n1t5u0mKe. fficiency (QE) of 32%, and a peak specific detectivity of

Theory and Experimental

Results and Discussion

The peak higher than