Nibir Dhar

By Ashok K. Sood, Zhong Lin Wang, Dennis L. Polla, Nibir K. Dhar, Tariq Manzur and A.F.M. Anwar

Part of the book: Optoelectronic Devices and Properties

By Nibir K. Dhar, Ravi Dat and Ashok K. Sood

Part of the book: Optoelectronics

By Ashok K. Sood, John W. Zeller, Roger E. Welser, Yash R. Puri, Nibir K. Dhar, Priyalal S. Wijewarnasuriya and Sanjay Krishna

The implementation of strained layer superlattices (SLS) for detection of infrared (IR) radiation has enabled compact, high performance IR detectors and two-dimensional focal plane arrays (FPAs). Since initially proposed three decades ago, SLS detectors exploiting type II band structures existing in the InAs/GaSb material system have become integral components in high resolution thermal detection and imaging systems. The extensive technological progress occurring in this area is attributed in part to the band structure flexibility offered by the nearly lattice-matched InAs/AlSb/Ga(In)Sb material system, enabling the operating IR wavelength range to be tailored through adjustment of the constituent strained layer compositions and/or thicknesses. This has led to the development of many advanced type II SLS device concepts and architectures for low-noise detectors and FPAs operating from the short-wavelength infrared (SWIR) to very long-wavelength infrared (VLWIR) bands. These include double heterostructures and unipolar-barrier structures such as graded-gap M-, W-, and N-structures, nBn, pMp, and pBn detectors, and complementary barrier infrared detector (CBIRD) and pBiBn designs. These diverse type II SLS detector architectures have provided researchers with expanded capabilities to optimize detector and FPA performance to further benefit a broad range of electro-optical/IR applications.

Part of the book: Two-dimensional Materials for Photodetector