Plasmonically enhanced absorption in colloidal metal/semiconductor nanocomposites

Abstract

Colloidal Quantum Dots (CQDs) are the route for low cost high eficiency photodetectors. Photoconductors are limited by the noise arising from high dark current densities, what is typically overcome reducing device's active area. However, this technique also reduces their photoresponse, and their optical absorption must be maintained as the volume is reduced. We study the use of plasmonics for that purpose, and present simulation results for solution-processed structures compatible with these techniques, showing up to a 13-fold enhancement in absorption. We present experimental results of a PbS CQDs photoconductor, fabricated using a novel CQDs functionalization, and venture the potential of these devices complemented with the shown promising techniques.