Evaluation of the photoinduced electron relaxation dynamics of Cu1.8S quantum dots

Abstract

Cu_1.8S quantum dots were prepared by using a single-source-precursor type method and investigated in the light of opto-electronic applications. With femtosecond time-resolved transient absorption measurements, the electron relaxation as well as their trapping dynamics could be evaluated. The measurements reveal that the largest and the smallest QD samples prepared exhibit the longest mobility lifetimes, and that the electron-hole relaxation dynamics is strongly dependent on the occurrence of trapping sites. Based on the argument of optical response, it appears that the largest prepared Cu_1.8S QDs with band gap energy of 2.35 eV are preferred candidates for opto-electronic device fabrication.