Paper
17 July 2000 GaAs-based CCD structure for MWIR/LWIR imaging applications
Geoffrey W. Taylor, Chi-Keung Kwan, Tuo Li
Author Affiliations +
Abstract
A new approach to sensing with intersubband absorption is introduced. In contrast to the conventional Quantum Well Infrared Photodetector (QWIP) which is a multi-quantum well device, our structure has 1 - 3 wells and uses resonant enhancement to achieve nearly complete absorption. In the QWIP the dark current is limited by the quantum well barrier in the range of 0.125 ev and thus cryogenic cooling is required in general to achieve BLIP operation. In the new structure, the dark current is limited by the band gap of GaAs/AlGaAs layers (>= 1.4 eV). This difference implies that BLIP operation may be possible near room temperature. The detecting quantum well is used to form the storage well of an active pixel or a CCD device and the intersubband absorption mechanism removes charge from the quantum well starting from the full well condition. The state of depletion of the well is then clocked to the output amplifier as in a conventional CCD using noise reduction techniques such as correlated double sampling. Therefore, the hybrid bump bonding of the Si ROIC is no longer required. In this paper, we describe the concept and its advantage vis-a-vis the existing approach and a preliminary analysis of the sensitivity of the detection.
© (2000) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Geoffrey W. Taylor, Chi-Keung Kwan, and Tuo Li "GaAs-based CCD structure for MWIR/LWIR imaging applications", Proc. SPIE 4028, Infrared Detectors and Focal Plane Arrays VI, (17 July 2000); https://doi.org/10.1117/12.391736
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KEYWORDS
Quantum wells

Charge-coupled devices

Quantum well infrared photodetectors

Absorption

Sensors

Doping

Interfaces

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