Development of High Performance Multicolor Quantum Well Infrared Photodetectors and Studies of Enhancing Light Coupling and Radiation Effects in QWIPs

Download or read book Development of High Performance Multicolor Quantum Well Infrared Photodetectors and Studies of Enhancing Light Coupling and Radiation Effects in QWIPs written by and published by . This book was released on 1999 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this report, we present the design, fabrication, and characterization of several high performance multi-color and broadband quantum well infrared photodetectors (QWIPs) for both MWIR and LWIR applications. The report covers tasks performed during the period from March 3, 1998 through July 10, 1999. A very high sensitivity, high-strain, multi-color triple-coupled (TC- ) QWIP using InGaAs/AlGaAs/InGaAs material systems has been developed in this project for LWIR multi-color detection. A two-stack InGaAs/AlGaAs/InGaAs TC-QWIP and InGaAs/AlGaAs TC-QWIP has been developed for the LWIR and MWIR dual-band detection. In addition, a high-strain InGaAs/GaAs TC-QWIP with and without two-dimensional (2-D) grating coupler has been designed, fabricated, and characterized for the LWIR detection. This device shows very high responsivity under 450 back-illumination. Several broadband (BB- ) QWIPs have been developed for the LWIR detection. These include (1) two-stack, five-well n-type InGaAs/AlGaAs broadband (BB- ) QWIPs with 3- and 7-period QWs in the unit cell, (2) 3- and 4-well n-type BB-QWIPs, and (3) two 3- and 4- well p-type BB-QWIPs. In addition, a three-stack InGaAs/AlGaAs/InGaAs BB TC-QWIP grown on GaAs substrate has been developed for LWIR detection, which has a FWHM spectral bandwidth twice larger than the single-stack TC-QWIP. Finally, a MWIR InGaAs/InAlAs TC-QWIP grown on InP substrate, operating up to T = 116K with excellent device performance, has also been demonstrated. Four journal papers and six conference papers have been published and presented from this work.