Carrier dynamics in InS nanowires grown via chemical vapor deposition

Abstract

Transient femtosecond absorption spectroscopy and timecorrelating single photon counting (TCSPC) photoluminescence (PL) were employed to study InS nanowires (NWs) grown by chemical vapor deposition (CVD) and determine the relaxation mechanisms in these nanostructures. Intensity dependent measurements revealed that Auger recombination plays an important role in the relaxation of photogenerated carriers at fluences larger than 0.4×10 15 photons/cm 2. Calculations provided an estimated of the Auger recombination coefficient to be 1.1±0.5×10 -31 cm 6/s. At the low fluence regime TCSPC PL revealed three relaxation mechanisms with time constants ranging from ps to nanosecond providing evidence of the importance of non-radiative decay channels associated with defect/trap states within the NWs. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.