Charge Transport in Nanoparticle Assemblies

Abstract

6 ×10 -2 '' '' '' Ag (7 ( 0.63) '' '' 1.5×10 -2 '' '' '' Ag (7 ( 0.64) '' '' 2.4×10 -3 '' '' '' Ag (7 ( 0.70) '' '' 1.2×10 -3 '' '' '' Ag (7 ( 0.96) '' '' 1.2×10 -4 '' '' '' Au (2 ( 0.2) C 4S 1.01 1.6×10 -3 Langmuir Chen 135 '' '' 0.90 2.7×10 -3 '' '' '' '' 0.87 3.3×10 -3 '' '' '' '' 0.84 3.7×10 -3 '' '' '' '' 0.82 4.1×10 -3 '' '' '' '' 0.80 5.0×10 -3 '' '' '' C 5S 1.23 8.2×10 -4 '' '' '' '' 1.14 8.2×10 -4 '' '' '' '' 1.06 8.2×10 -4 '' '' '' '' 1.02 1.1×10 -3 '' '' '' '' 0.98 1.3×10 -3 '' '' '' '' 0.95 3.5×10 -3 '' '' '' '' 0.92 6.8×10 -3 '' '' Au (4.6-6.5) C 12S 1.5-2.6 A (38) DC Parthasarathy et al. 272 Au (1.6 ( 0.16) C6S 0.9 1 ×10 -5 LS Liljeroth et al. 142 '' C12S 1.4 6 ×10 -6 '' '' Au (6.6 ( 0.8) C 12S 2.5 2 ×10 -3 '' '' '' '' 1.8 5 ×10 -3 '' '' '' '' 1.5 8 ×10 -3 '' '' '' '' 1.3 1 ×10 -2 '' ''a R ) NP radius, s ) inter-NP separation, σ ) conductivity, and Ea ) activation energy. b CnS ) CH3(CH2)n-1SH; CnS2 ) HS(CH2)nSH; 1 ) 1,4-di-(4-isocyanophenylethynyl)-2-ethylbenzene; and 2 ) 2,5′′-bis(acetylthio)-5,2′,5′,2′′-terthienyl. c A ) Arrhenius; nA ) non-Arrhenius; M ) metallic; nM ) nonmetallic; and MIT ) metal-insulator transition. d DC ) drop-casting; LB ) Langmuir-Blodgett; LS ) Langmuir-Schaefer; and SC ) spin-casting.

Advancing colloidal quantum dot photovoltaic technology

“…Additionally, ligands help to protect CQDs from oxidative degradation, and can facilitate electronic coupling between neighboring CQDs in the film phase. Long organic ligands, however, can act as electronic tunneling barriers, where the rate of charge transport through the barrier decreases exponentially with the barrier width and the square root of the barrier height [89][90][91][92].…”

Thioacetic-Acid Capped PbS Quantum Dot Solids Exhibiting Thermally Activated Charge Hopping Transport

“…After the ligand exchange from the OA (C 17 H 33 COOH) to TAA (CH 3 COSH) on the surface of a PbS quantum dot, the number of carbon atoms on the alkyl chain was decreased by about 17 times, according to the equation G-G 0 exp(-n), where G 0 is the pre-factor,  is the decay constant (~1.2) and n is the number of carbon atoms on the alkyl chain. 49 At the initial state of baking at 80 o C, the conductivity of the PbS QDs thin films is expected to increase by about 8.3 orders of magnitude after the ligand exchange process: (5) where G 1 and G 2 are the conductances of the PbS-OA QDs and PbS-TAA QDs thin films.…”

On the application potential of gold nanoparticles in nanoelectronics and biomedicine

“…In the following, we will briefly summarize the basic principles of SET and present selected examples involving STMs and the nanogap set-up with respect to electrical addressing and device formation. Concerning the electrochemical properties, which also reflect Coulomb charging effects, we refer to recent reviews (Laaksonen et al 2008;Zabet-Khosousi & Dhirani 2008), since a detailed description would far exceed the scope of this review. It should just briefly be mentioned that multiple charging becomes feasible in an electrochemical environment (Mertens et al 2009), which could be relevant for multistate logic (Albrecht et al 2007).…”

“…Thereby, usually, the tip-to-sample distance is fixed and, depending on the tip-to-sample bias, the tunnelling current, differential conductance and so on are measured. The obtained spectroscopic data provide information about local electronic characteristics of the sample, such as density of states (Zabet-Khosousi & Dhirani 2008). One advantage of STM/STS measurements is that the individual cluster can be topographically and spectroscopically analysed in one single experiment, which ensures reliable data.…”

“…However, nowadays, electron-beam lithographic techniques allow already nanogap configurations with gap separations of approximately 10-100 nm. Furthermore, gaps of less than 10 nm can be created by, for example, mechanical breaking or electromigration (Zabet-Khosousi & Dhirani 2008). This means, in principle, that addressing of individual AuNPs is achievable, although, nevertheless, the number and the orientation/topologies of AuNPs in such a nanogap are still hard to control.…”