Quantum dot nanocolumn photodetectors for light detection in the infrared

Colloidal quantum dots absorbing in the infrared are filled into nanoporous alumina membranes to form narrow columns with aspect ratios of 300:1. The columns define the charge carrier path vertical through the ordered pore structure of the membrane. Electrical transport and photocurrent of various quantum dot column photodetectors based on two different nanomaterials, namely, HgTe and PbS quantum dots, with different quantum dot sizes are investigated. Photocurrents up to long wavelengths of 3μm are demonstrated.