Please use this identifier to cite or link to this item:
Title: Photophysics of PbS quantum dot films capped with arsenic sulfide ligands
Authors: Tsokkou, Demetra 
Papagiorgis, Paris 
Protesescu, Loredana 
Kovalenko, Maksym V. 
Choulis, Stelios A. 
Christofides, Constantinos 
Itskos, Grigorios 
Othonos, Andreas 
Keywords: Carrier dynamics;Ligand exchange;Photophysics;Quantum dots;Spectroscopy
Category: Chemical Sciences
Field: Natural Sciences
Issue Date: 13-May-2014
Publisher: Wiley-VCH Verlag
Source: Advanced Energy Materials, 2014, Volume 4, Issue 7, Article number 1301547
metadata.dc.doi: 10.1002/aenm.201301547
Abstract: PbS quantum dots (QDs) of different sizes capped with short (NH 4)3AsS3 inorganic ligands are produced via ligand exchange processes from oleate-capped PbS QDs. The solid-state photophysical properties of the control organic-capped and the inorganic-ligand-capped QDs are investigated to determine their potential for optoelectronic applications. Ultrafast transient transmission shows that in the oleate-capped QDs, carrier recombination at sub-nanosecond scales occurs via Auger recombination, traps, and surface states. At longer times, intense signals associated with radiative recombination are obtained. After ligand exchange, the QDs become decorated with (NH4)3AsS3 complexes and relaxation is dominated by efficient carrier transfer to the ligand states on timescales as fast as ≈2 ps, which competes with carrier thermalization to the QD band edge states. Recombination channels present in the oleate-capped QDs, such as radiative and Auger recombination, appear quenched in the inorganic-capped QDs. Evidence of efficient carrier trapping at shallow ligand states, which appears more intense under excitation above the (NH 4)3AsS3 gap, is provided. A detailed band diagram of the various relaxation and recombination processes is proposed that comprehensively describes the photophysics of the QD systems studied.
ISSN: 16146832
Rights: © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Type: Article
Appears in Collections:Άρθρα/Articles

Show full item record

Page view(s) 50

Last Week
Last month
checked on Feb 20, 2019

Google ScholarTM


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.