Plasmonic CdZnO nanoparticles for enhanced GaAs-based quantum well intersubband absorption

In this work we propose the use of self-assembled CdZnO nanoparticles as a route to improve power absorption in midinfrared GaAs-based quantum well infrared photodetectors (QWIPs). We experimentally demonstrate low temperature growth of CdZnO nanoparticles on GaAs and characterize their plasmonic response in the mid-IR. Computational analysis of the plasmonic resonances coupled to intersubband transitions in GaAs quantum wells show that intersubband absorption at normal incidence, forbidden by quantum selection rules, can be obtained. Gains in the quantum well power absorption as high as 5.5 are also reported.