Capture and transit-time electron effects in high-frequency operation of multiple quantum well infrared photodetectors

• Published in: Physica. E, Low-dimensional systems & nanostructures Vol. 2; no. 1; pp. 142 - 145
• Main Authors: Ryzhii, V, Khmyrova, I, Ryzhii, M
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-07-1998
• Subjects: Bandwidth; Capture rate; Frequency-dependent responsivity; Infrared photodetectors; Quantum well; Transit time; Infrared photodetectors; Quantum well; Capture rate; Transit time; Frequency-dependent responsivity; Bandwidth
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/S1386-9477(98)00031-9

An analytical model of multiple quantum well infrared photodetectors (QWIPs) is used to calculate their frequency-dependent responsivity and bandwidth. The device model takes into account all electron processes important for the QWIP high-frequency operation. It is shown that the roll-off of the frequency-dependent responsivity and, consequently, the bandwidth are determined by the electron transit time across the inter-QW barrier, the capture probability of electrons in the QWs and the number of the latters. The bandwidth can be expanded by using the QW structures specially designed to have large electron capture probability.