Photonic crystal-enhanced quantum dot infrared photodetectors

摘要

Quantum dot infrared photodetectors (QDIPs) promise improved performance over existing technologies in the form ofhigher temperature operation and normal-incidence detection. Variation in the size of self-assembled quantum dots leadsto a broadened spectral response, which is undesirable for multi-color detection. Photonic crystal slabs can filter thetransmission of normally-incident light using Fano resonances, and thus may be integrated with QDIPs to create anarrowband detector. Finite-difference time-domain simulations were used to optimize such a filter for QDIPs grown bymetal-organic chemical vapor deposition. The simulations predict that the integrated detector could show up to 76%decrease in the detector linewidth, with a tunable peak location. These devices were then fabricated by standard opticallithography, however the spectral width of the integrated device was similar to that of the unfiltered QDIP. This isattributed to imperfections in the filter, so alternative fabrication methods are discussed for future processing.