The photocurrent noise has been investigated in Quantum Well Infrared Photodetectors (QWIPs) having identical growth sequence, layer width and composition, but different number of wells. It has been found that the power spectral density exhibits characteristic features related to the discrete structure of the device. This behavior might be caused by the strong potential nonuniformity arising as a consequence of the imbalance between the current injected at the emitter and the stream of photoelectrons drifting through the structure, which is also responsible for the anomalies in the steady-state and transient photoconductivity. In the present work, we will add further evidence to our preliminary study by presenting results of the power spectral density obtained by numerical solution of the continuity equation of the electrons in the continuum state, with a discrete distribution of the electric field in the active region, instead of the homogeneous one valid for conventional photodetectors.

Date Published: 16 May 2003
PDF: 7 pages
Proc. SPIE 5111, Fluctuations and Noise in Photonics and Quantum Optics, (16 May 2003); doi: 10.1117/12.497040

Published in SPIE Proceedings Vol. 5111:
Fluctuations and Noise in Photonics and Quantum Optics
Derek Abbott; Jeffrey H. Shapiro; Yoshihisa Yamamoto, Editor(s)