Air-Stable Short-Wave Infrared Pbs Colloidal Quantum Dot Photoconductors Passivated With Al2o3 Atomic Layer Deposition

A PbS colloidal quantum dot photoconductor with Al2O3 atomic layer deposition (ALD) passivation for air-stable operation is presented. Two different types of inorganic ligands for the quantum dots, S2- and OH-, are investigated. PbS/S2- photoconductors with a cut-off wavelength up to 2.4 mu m are obtained, and a responsivity up to 50 A/W at 1550 nm is reported. The corresponding specific detectivity is similar to 3.4 x 10(8) Jones at 230 K. The 3-dB bandwidth of the PbS/S2- and PbS/OH- photodetectors is 40 Hz and 11 Hz, respectively. (C) 2014 AIP Publishing LLC.