Journal ArticleDOI
Structural, Optical and Electrical Properties of Self-Assembled Films of PbSe Nanocrystals Treated with 1,2-Ethanedithiol
TLDR
The LbL process described here is a general strategy for producing uniform, conductive nanocrystal films for applications in optoelectronics and solar energy conversion.Abstract:
We describe the structural, optical, and electrical properties of high-quality films of PbSe nanocrystals fabricated by a layer-by-layer (LbL) dip-coating method that utilizes 1,2-ethanedithiol (EDT) as an insolubilizing agent. Comparative characterization of nanocrystal films made by spin-coating and by the LbL process shows that EDT quantitatively displaces oleic acid on the PbSe surface, causing a large volume loss that electronically couples the nanocrystals while severely degrading their positional and crystallographic order of the films. Field-effect transistors based on EDT-treated films are moderately conductive and ambipolar in the dark, becoming p-type and 30–60 times more conductive under 300 mW cm−2 broadband illumination. The nanocrystal films oxidize rapidly in air to yield, after short air exposures, highly conductive p-type solids. The LbL process described here is a general strategy for producing uniform, conductive nanocrystal films for applications in optoelectronics and solar energy co...read more
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Journal ArticleDOI
PbS Nanocrystals Functionalized with a Short-Chain, Ionic, Dithiol Ligand
Abstract: Ligand exchange from oleic acid-capped PbS nanocrystals was used to prepare sodium 2,3-dimercaptopropanesulfonate (DT) functionalized, water-soluble PbS nanocrystals. Oxygen-free aqueous solutions of the PbS-DT nanocrystals were observed to be stable for more than five months. In aerated solutions, the PbS-DT nanocrystals were observed to be stable to precipitation for more than 24 h in the dark, with precipitation accelerated by illumination. Under both light and dark conditions, the PbS nanocrystals prepared with the chelating DT ligand were observed to be more stable to precipitation than nanocrystals prepared with the monothiol analogue sodium 3-mercaptopropanesulfonate (MT). The greater stability of the PbS-DT nanocrystals is argued to be due to the formation of oligodisulfides that remain partially bound to the nanocrystal surface thereby inhibiting precipitation. Support for this comes from the fact that the PbS-DT nanocrystals were not observed to substantially accelerate the photooxidation of excess DT ligand, in contrast to the behavior of the PbS-MT nanocrystals in the presence of excess ligand. Due to the compact size of the DT ligand, thin films of PbS-DT nanocrystals were observed to exhibit much greater photoconductivity than PbS nanocrystals capped with the longer chain oleic acid ligand. Responsivities of greater than 1 A/W in the near-infrared were achieved with thin films of PbS-DT NCs on interdigitated array electrodes.
Journal ArticleDOI
A facile one-step approach for the synthesis and assembly of copper and copper-oxide nanocrystals
TL;DR: In this article, a simple one-step approach for the formation of close packed films of copper and copper oxide nanoparticles is described, which enables an easy and reproducible process for the synthesis and assembly of metal oxide nanostructures.
Journal ArticleDOI
Lead Halide Perovskite Quantum Dots To Enhance the Power Conversion Efficiency of Organic Solar Cells.
Néstor Guijarro,Liang Yao,Florian Le Formal,Rebekah A. Wells,Yongpeng Liu,Barbara Primera Darwich,Lucie Navratilova,Han-Hee Cho,Jun-Ho Yum,Kevin Sivula +9 more
TL;DR: The first demonstration of integrating CsPbI3 QDs into a conventional organic solar cell (OSC) by embedding the LHP QDs in a donor:acceptor (PTB7-Th:PC71BM) bulk heterojunction is presented.
Journal ArticleDOI
Advances in nanostructured homojunction solar cells and photovoltaic materials
Nisar Ali,R. Ahmed,Jing Ting Luo,Jing Ting Luo,Mingkui Wang,Abul Kalam,Abul Kalam,Abdullah G. Al-Sehemi,Abdullah G. Al-Sehemi,Yong Qing Fu +9 more
TL;DR: In this article, the development of homojunction solar cells with two-dimensional (or thin film) based materials, one-dimensional materials (nanowire/nanorods/nanotube), and zero-dimensional material (nanodots and quantum dots) is reviewed.
Journal ArticleDOI
Virtually Bare Nanocrystal Surfaces: Significantly Enhanced Electrical Transport in CuInSe2and CuIn1−xGaxSe2Thin Films upon Ligand Exchange with Thermally Degradable 1-Ethyl-5-Thiotetrazole
Jannika Lauth,Jakob Marbach,Andreas Meyer,Sedat Dogan,Christian Klinke,Andreas Kornowski,Horst Weller +6 more
TL;DR: In this paper, a facile and safe ligand exchange method for readily synthesized CuInSe2 (CIS) and CIGS (CIGS) nanocrystals (NCs) from oleylamine to 1-ethyl-5-thiotetrazole, preserving the colloidal stability of the chalcopyrite structure, is presented.
References
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Journal ArticleDOI
Two-dimensional charge transport in self-organized, high-mobility conjugated polymers
Henning Sirringhaus,Peter J. Brown,Richard H. Friend,Martin Nielsen,Klaus Bechgaard,B.M.W. Langeveld-Voss,A. J. H. Spiering,René A. J. Janssen,E. W. Meijer,P. T. Herwig,Dago M. de Leeuw +10 more
TL;DR: In this article, the authors used thin-film, field effect transistor structures to probe the transport properties of the ordered microcrystalline domains in the conjugated polymer poly(3-hexylthiophene), P3HT.
Journal ArticleDOI
Light-emitting diodes made from cadmium selenide nanocrystals and a semiconducting polymer
TL;DR: In this article, a hybrid organic/inorganic electroluminescent device was constructed based on the recombination of holes injected into a layer of semiconducting p-paraphenylene vinylene (PPV) with electrons injected into the multilayer film of cadmium selenide nanocrystals.
Journal Article
Light-emitting diodes made from cadmium selenide nanocrystals and a semiconducting polymer
TL;DR: In this article, a hybrid organic/inorganic electroluminescent device was constructed based on the recombination of holes injected into a layer of semiconducting p-paraphenylene vinylene (PPV) with electrons injected into the multilayer film of cadmium selenide nanocrystals.
Journal ArticleDOI
Electroluminescence from single monolayers of nanocrystals in molecular organic devices
TL;DR: A hybrid light-emitting diode (LED) that combines the ease of processability of organic materials with the narrow-band, efficient luminescence of colloidal quantum dots (QDs) is demonstrated and a 25-fold improvement in luminescent efficiency is observed.
Journal ArticleDOI
Quantum dot solar cells
TL;DR: In this article, three QD solar cell configurations are described: (1) photoelectrodes comprising QD arrays, (2) QD-sensitized nanocrystalline TiO 2, and (3) QDs dispersed in a blend of electron- and hole-conducting polymers.