Precise Control of the Oxidation State of PbS Quantum Dots Using Rapid Thermal Annealing for Infrared Photodetectors

Abstract

We report the effect of oxidation on PbS quantum dot (QD) photodetectors using rapid thermal annealing (RTA) and furnace annealing in air at different durations and temperatures. Air-annealed QD films using RTA had an improved specific detectivity of up to 1.51 X 10(12) Jones with a responsivity of up to 1.895 X 10(3) A/W at 1 kHz. We used transient photocurrent decay measurements, X-ray photoelectron spectroscopy, and frequency response measurements to investigate the origin of this effect. We found that short-term annealing with RTA in air increases the product of carrier mobility and carrier lifetime (mu tau) of the QD photoconductors, which leads to high photoconductive gain and bandwidth.