Show simple item record

dc.contributor.authorZhitomirsky, David
dc.contributor.authorVoznyy, Oleksandr
dc.contributor.authorHoogland, Sjoerd
dc.contributor.authorSargent, Edward H.
dc.date.accessioned2016-02-25T13:41:07Z
dc.date.available2016-02-25T13:41:07Z
dc.date.issued2013-05-31
dc.identifier.citationZhitomirsky D, Voznyy O, Hoogland S, Sargent EH (2013) Measuring Charge Carrier Diffusion in Coupled Colloidal Quantum Dot Solids. ACS Nano 7: 5282–5290. Available: http://dx.doi.org/10.1021/nn402197a.
dc.identifier.issn1936-0851
dc.identifier.issn1936-086X
dc.identifier.pmid23701285
dc.identifier.doi10.1021/nn402197a
dc.identifier.urihttp://hdl.handle.net/10754/598782
dc.description.abstractColloidal quantum dots (CQDs) are attractive materials for inexpensive, room-temperature-, and solution-processed optoelectronic devices. A high carrier diffusion length is desirable for many CQD device applications. In this work we develop two new experimental methods to investigate charge carrier diffusion in coupled CQD solids under charge-neutral, i.e., undepleted, conditions. The methods take advantage of the quantum-size-effect tunability of our materials, utilizing a smaller-bandgap population of quantum dots as a reporter system. We develop analytical models of diffusion in 1D and 3D structures that allow direct extraction of diffusion length from convenient parametric plots and purely optical measurements. We measure several CQD solids fabricated using a number of distinct methods and having significantly different doping and surface ligand treatments. We find that CQD materials recently reported to achieve a certified power conversion efficiency of 7% with hybrid organic-inorganic passivation have a diffusion length of 80 ± 10 nm. The model further allows us to extract the lifetime, trap density, mobility, and diffusion coefficient independently in each material system. This work will facilitate further progress in extending the diffusion length, ultimately leading to high-quality CQD solid semiconducting materials and improved CQD optoelectronic devices, including CQD solar cells. © 2013 American Chemical Society.
dc.description.sponsorshipThis publication is based in part on work supported by Award KUS-11-009-21, made by King Abdullah University of Science and Technology (KAUST), by the Ontario Research Fund Research Excellence Program, and by the Natural Sciences and Engineering Research Council (NSERC) of Canada. David Zhitomirsky would like to acknowledge his NSERC CGS D scholarship. We thank Angstrom Engineering, Inc. and Innovative Technology, Inc. for useful discussions regarding material deposition methods and control of the glovebox environment, respectively. The authors would like to acknowledge P. Maraghechi for aid in ellipsometry measurements and technical assistance from E. Palmiano, R. Wolowiec, and D. Kopilovic.
dc.publisherAmerican Chemical Society (ACS)
dc.subjectcolloidal quantum dots
dc.subjectdiffusion length
dc.subjectlifetime
dc.subjectmobility
dc.subjecttransport
dc.titleMeasuring Charge Carrier Diffusion in Coupled Colloidal Quantum Dot Solids
dc.typeArticle
dc.identifier.journalACS Nano
dc.contributor.institutionUniversity of Toronto, Toronto, Canada
kaust.grant.numberKUS-11-009-21
dc.date.published-online2013-05-31
dc.date.published-print2013-06-25


This item appears in the following Collection(s)

Show simple item record