Journal ArticleDOI
Solution-based stoichiometric control over charge transport in nanocrystalline CdSe devices.
David Kim,Aaron T. Fafarman,Benjamin T. Diroll,Silvia H. Chan,Thomas R. Gordon,Christopher B. Murray,Cherie R. Kagan +6 more
TLDR
Using colloidal CdSe nanowire (NW) field-effect transistors (FETs), the dependence of carrier transport on surface stoichiometry is demonstrated by chemically manipulating the atomic composition of the NW surface to support the existence of an indium-chalcogen interaction at the surface rather than in the core of theNW.Abstract:
Using colloidal CdSe nanowire (NW) field-effect transistors (FETs), we demonstrated the dependence of carrier transport on surface stoichiometry by chemically manipulating the atomic composition of the NW surface. A mild, room-temperature, wet-chemical process was devised to introduce cadmium, selenium, or sulfur adatoms at the surface of the NWs in completed devices. Changes in surface composition were tested for by energy dispersive spectroscopy and inductively coupled plasma-atomic emission spectroscopy and through the use of the vibrational reporter thiocyanate. We found that treatment with cadmium acetate enhances electron currents, while treatment with sodium selenide or sodium sulfide suppressed them. The efficacy of doping CdSe NWs through subsequent thermal diffusion of indium was highly dependent on the surface composition. While selenium-enriched CdSe NW FETs were characterized by little to no electron currents, when combined with indium, they yielded semimetallic devices. Sulfur-enriched, indi...read more
Citations
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Journal ArticleDOI
Prospects of Nanoscience with Nanocrystals
Maksym V. Kovalenko,Liberato Manna,Liberato Manna,Andreu Cabot,Zeger Hens,Dmitri V. Talapin,Dmitri V. Talapin,Cherie R. Kagan,Victor I. Klimov,Andrey L. Rogach,Peter Reiss,Delia J. Milliron,Philippe Guyot-Sionnnest,Gerasimos Konstantatos,Wolfgang J. Parak,Taeghwan Hyeon,Brian A. Korgel,Christopher B. Murray,Wolfgang Heiss,Wolfgang Heiss +19 more
TL;DR: The state of the art in research on colloidal NCs is reviewed focusing on the most recent works published in the last 2 years, where semiconductor NCs hold unique promise for near- and mid-infrared technologies, where very few semiconductor materials are available.
Journal ArticleDOI
Ligand exchange and the stoichiometry of metal chalcogenide nanocrystals: spectroscopic observation of facile metal-carboxylate displacement and binding.
TL;DR: The results demonstrate that nanocrystals lack a single chemical formula, but are instead dynamic structures with concentration-dependent compositions, and suggest that ligands displace L-M(O2CR)2 by cooperatively complexing the displaced metal ion as well as the nanocrystal.
Journal ArticleDOI
Nonthermal Plasma Synthesis of Nanocrystals: Fundamental Principles, Materials, and Applications
Uwe Kortshagen,R. Mohan Sankaran,Rui N. Pereira,Rui N. Pereira,Steven L. Girshick,Jeslin J. Wu,Eray S. Aydil +6 more
TL;DR: The fundamentals of nanocrystal formation in plasmas are discussed, practical implementations of plasma reactors are reviewed, the materials that have been produced with nonthermal plAsmas and surface chemistries that have be developed are surveyed, and an overview of applications of plasma-synthesized nanocrystals is provided.
Journal ArticleDOI
Designing High-Performance PbS and PbSe Nanocrystal Electronic Devices through Stepwise, Post-Synthesis, Colloidal Atomic Layer Deposition
Soong Ju Oh,Nathaniel E. Berry,Ji Hyuk Choi,E. Ashley Gaulding,Hangfei Lin,Taejong Paik,Benjamin T. Diroll,Shin Muramoto,Christopher B. Murray,Cherie R. Kagan +9 more
TL;DR: It is found that unlike chalcogen-enriched NC surfaces that are structurally, optically, and electronically unstable, lead chloride treatment creates a well-passivated shell that stabilizes the NCs.
Journal ArticleDOI
Air-Stable n-Doped Colloidal HgS Quantum Dots.
TL;DR: This is the first time that stable carriers are present in the quantum state of strongly confined quantum dot in ambient conditions, attributed to the rigid shifts of the valence and conduction band with respect to the environment, similar to the sensitivity of the work function of surfaces to adsorbates.
References
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Journal ArticleDOI
PbSe Nanocrystal Solids for n- and p-Channel Thin Film Field-Effect Transistors
TL;DR: These nanocrystal field-effect transistors allow reversible switching between n- and p-transport, providing options for complementary metal oxide semiconductor circuits and enabling a range of low-cost, large-area electronic, optoelectronic, thermoelectric, and sensing applications.
Journal ArticleDOI
Colloidal-quantum-dot photovoltaics using atomic-ligand passivation
Jiang Tang,Kyle W. Kemp,Sjoerd Hoogland,Kwangseob Jeong,Huan Liu,Huan Liu,Larissa Levina,Melissa Furukawa,Xihua Wang,Ratan Debnath,Dongkyu Cha,Kang Wei Chou,Armin Fischer,Aram Amassian,John B. Asbury,Edward H. Sargent +15 more
TL;DR: An atomic ligand strategy is established that makes use of monovalent halide anions to enhance electronic transport and successfully passivate surface defects in PbS CQD films that shows up to 6% solar AM1.5G power-conversion efficiency.
Journal ArticleDOI
Ultralow-power organic complementary circuits
TL;DR: This work demonstrates an organic circuit with very low power consumption that uses a self-assembled monolayer gate dielectric and two different air-stable molecular semiconductors (pentacene and hexadecafluorocopperphthalocyanine, F16CuPc) to implement transistors, circuits, displays and sensors on arbitrary substrates.
Journal ArticleDOI
Photochemistry of colloidal semiconductors. 20. Surface modification and stability of strong luminescing CdS particles
TL;DR: The preparation of CdS sols with a mean diameter between 40 and 60 A and a relatively narrow size distribution is described in this paper, where the colloids could be separated as solids, which in turn could be redissolved to give solutions of some 10/sup -2/M.
Journal ArticleDOI
Hybrid passivated colloidal quantum dot solids
Alexander H. Ip,Susanna M. Thon,Sjoerd Hoogland,Oleksandr Voznyy,David Zhitomirsky,Ratan Debnath,Larissa Levina,Lisa R. Rollny,Graham H. Carey,Armin Fischer,Kyle W. Kemp,Illan J. Kramer,Zhijun Ning,André J. Labelle,Kang Wei Chou,Aram Amassian,Edward H. Sargent +16 more
TL;DR: The density of midgap trap states in CQD solids is quantified and shown to be limited by electron-hole recombination due to these states, and a robust hybrid passivation scheme is developed that can passivate trap sites that are inaccessible to much larger organic ligands.