Plasmonic light trapping leads to responsivity increase in colloidal quantum dot photodetectors

We report broadband responsivity enhancement in PbScolloidalquantum dot (CQDs) photoconductive photodetectors due to absorption increase offered by a plasmonicscattering layer of Ag metal nanoparticles. Responsivity enhancements are observed in the near infrared with a maximum 2.4-fold increase near the absorption band edge of ∼1 μm for ∼400 nm thick devices. Additionally, we study the effect of the mode structure on the efficiency of light trapping provided by random nanoparticlescattering in CQD films and provide insights for plasmonicscattering enhancement in CQD thin films