Exciton relaxation in PbS quantum dots

Exciton relaxation in PbS quantum dots (QDs) in glass and tetrachloroethylene have been investigated and the radiative and non‐radiative relaxation rates of the lowest 1S–1S state have been measured. An estimate of the carrier intra‐band transition rates and their transfer efficiency is calculated. The dependence of the exciton dynamics on the QD surface properties is presented and discussed. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) Lead sulfide (PbS) quantum dots with size of several nanometers provide tunable exciton transitions in the near‐infrared spectral range and attract attention from both fundamental and applied points of view. The letter reports on the results of investigation of size‐ and matrix‐dependent radiative and non‐radiative relaxation of photoexcited excitons in these zero‐dimensional semiconductor nanostructures.