New Findings on Quantum Dots from Johns Hopkins University Summarized (Engineering colloidal quantum dot solids within and beyond the mobility-invariant regime)
By a News Reporter-Staff News Editor at Journal of Engineering -- Current study results on Quantum Dots have been published. According to news reporting originating in Baltimore, Maryland, by VerticalNews journalists, research stated, "Colloidal quantum dots are attractive materials for efficient, low-cost and facile implementation of solution-processed optoelectronic devices. Despite impressive mobilities (1-30 cm(2)V(-1) s(-1)) reported for new classes of quantum dot solids, it is-surprisingly-the much lower-mobility (10(-3)-10(-2) cm(2) V(-1)s(-1)) solids that have produced the best photovoltaic performance."
The news reporters obtained a quote from the research from Johns Hopkins University, "Here we show that it is not mobility, but instead the average spacing among recombination centres that governs the diffusion length of charges in today's quantum dot solids. In this regime, colloidal quantum dot films do not benefit from further improvements in charge carrier mobility. We develop a device model that accurately predicts the thickness dependence and diffusion length dependence of devices. Direct diffusion length measurements suggest the solid-state ligand exchange procedure as a potential origin of the detrimental recombination centres."
According to the news reporters, the research concluded: "We then present a novel avenue for in-solution passivation with tightly bound chlorothiols that retain passivation from solution to film, achieving an 8.5% power conversion efficiency."
For more information on this research see: Engineering colloidal quantum dot solids within and beyond the mobility-invariant regime. Nature Communications, 2014;5():138-144. Nature Communications can be contacted at: Nature Publishing Group, Macmillan Building, 4 Crinan St, London N1 9XW, England. (Nature Publishing Group - www.nature.com/; Nature Communications - www.nature.com/ncomms/)
Our news correspondents report that additional information may be obtained by contacting D. Zhitomirsky, Johns Hopkins University, Dept. of Elect & Comp Engn, Baltimore, MD 21218, United States. Additional authors for this research include O. Voznyy, L. Levina, S. Hoogland, K.W. Kemp, A.H. Ip, S.M. Thon and E.H. Sargent.
Keywords for this news article include: Maryland, Baltimore, Engineering, Quantum Dots, United States, Nanotechnology, Emerging Technologies, North and Central America
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