Opt Quant Electron (2008) 40:1085–1090 DOI 10.1007/s11082-009-9271-8 An FDTD approach to the simulation of quantum-well infrared photodetectors Luca Stabellini · Wei Lu · Alfredo De Rossi · Thomas Antoni · Mathieu Carras · Stefano Trillo · Gaetano Bellanca Received: 19 September 2008 / Accepted: 21 January 2009 / Published online: 13 February 2009 © Springer Science+Business Media, LLC. 2009 Abstract A Finite Difference Time Domain approach is used to design and to optimize quantum-well based infrared photodetectors. Results showing the influence of some param- eters on the performance of these devices are presented and discussed. Keywords QWIP · Infrared detectors · Photodetectors · Finite difference time domain 1 Introduction Quantum-Well Infrared Photodetectors (QWIPs) have emerged as the most promising class of detectors for applications in the mid infrared domain (Levine 1993; Schneider 2006). These detectors are made from semiconductor materials which contain one or more quan- tum-wells, and can be integrated with electronics and optics to realize, for example, infrared cameras with a wide range of scientific and commercial applications (Costard and Bois 2007). QWIP technology relies on III-V heterostructures and takes advantage of the widely used GaAs processing. A very common well material, in fact, is the Gallium Arsenide (GaAs ), whereas the Aluminium Gallium Arsenide ( AlGaAs ) is a typical barrier one. QWIPs are able to work on either or both of the atmospheric transmission windows: band II (3 - 5 μm) and band III (8 - 12 μm). Low band-gap materials suited to detect such a long wavelengths (λ ≈ 10μm) are difficult to grow and fabricate. However, a low effective band-gap solution can be achieved by means of large gap semiconductors and quantum-wells that, exploiting intersubband absorption resulting from carrier transitions between energy states within the L. Stabellini · W. Lu · A. De Rossi Thales Research and Technology, Route Departementale, 128 91767 Palaiseau Cedex, France T. Antoni · M. Carras Alcatel Thales III-V Lab, Route Departementale, 128 91767 Palaiseau Cedex, France S. Trillo · G. Bellanca (B ) Department of Engineering, University of Ferrara, Via Saragat, 1 44100 Ferrara, Italy e-mail: gaetano.bellanca@unife.it 123