نتایج جستجو برای: hole recombination

تعداد نتایج: 107742  

2007
Farhan Rana

We calculate electron-hole generation and recombination rates for Coulomb scattering (Auger recombination and impact ionization) in Graphene. The conduction and valence band dispersion relation in Graphene together with energy and momentum conservation requirements restrict the phase space for Coulomb scattering so that electron-hole recombination times can be much longer than 1 ps for electron...

Journal: :Journal of chemical theory and computation 2013
Jennifer M Elward Arindam Chakraborty

Radius of quantum dot Exciton binding energy and electron-hole recombination probability are presented as the two important metrics for investigating effect of dot size on electronhole interaction in CdSe quantum dots. Direct computation of electron-hole recombination probability is challenging because it requires an accurate mathematical description of electron-hole wavefunction in the neighbo...

2004
Feng Wang Gordana Dukovic Louis E. Brus Tony F. Heinz

Time-resolved fluorescence measurements of single-walled carbon nanotubes (SWNTs) reveal rapid electron-hole pair annihilation when multiple electron-hole pairs are present in a nanotube. The process can be understood as Auger recombination with a rate of ,1 ps−1 for just two electron-hole pairs in a 380-nm long SWNT. This efficient nonradiative recombination reflects the strong carrier-carrier...

2008
Farhan Rana

We calculate electron-hole recombination rates for Auger scattering in Graphene. The conduction and valence band dispersion relation in Graphene together with energy and momentum conservation requirements restrict the phase space for Auger processes so that electron-hole recombination times can be much longer than 1 ps for electron-hole densities smaller than 1012 cm−2.

The relatively low power conversion efficiency (PCE) of quantum dot sensitized solar cells (QDSSCs) is attributed to charge recombination at the interfaces. Charge recombination process could be suppressed by coating the QD layer with a wide band gap semiconductor such as ZnS, which acts as a blocking layer between the QDs and hole transport material (HTM). In present study, to improve PCE of P...

Journal: :Physical review letters 2009
François Léonard A Alec Talin B S Swartzentruber S T Picraux

We present electronic transport measurements in individual Au-catalyst/Ge-nanowire interfaces demonstrating the presence of a Schottky barrier. Surprisingly, the small-bias conductance density increases with decreasing diameter. Theoretical calculations suggest that this effect arises because electron-hole recombination in the depletion region is the dominant charge transport mechanism, with a ...

Journal: :The Journal of chemical physics 2012
Jennifer M Elward Barbara Thallinger Arindam Chakraborty

The electron-hole explicitly correlated Hartree-Fock method (eh-XCHF) is presented as a general strategy for investigation of electron-hole correlation and computation of electron-hole recombination probability. The eh-XCHF method is a variational method which uses explicitly correlated wavefunction that depends on the electron-hole inter-particle distances. It is shown that the explicitly corr...

2017
Hongde Luo Adrie J. J. Bos Pieter Dorenbos

Two different charge carrier trapping processes have been investigated in RE2O2S:Ln3+ (RE = La, Gd, Y, and Lu; Ln = Ce, Pr, and Tb) and RE2O2S:M (M = Ti4+ and Eu3+). Cerium, praseodymium and terbium act as recombination centers and hole trapping centers while host intrinsic defects provide the electron trap. The captured electrons released from the intrinsic defects recombine at Ce4+, Pr4+, or ...

Journal: :Chemical communications 2012
Charles Y Cummings Frank Marken Laurence M Peter Asif A Tahir K G Upul Wijayantha

Rate constants for recombination and hole transfer during oxygen evolution at illuminated α-Fe(2)O(3) electrodes were measured by intensity-modulated photocurrent spectroscopy and found to be remarkably low. Treatment of the electrode with a Co(II) solution suppressed surface recombination but did not catalyse hole transfer. Intermediates in the reaction were detected spectroscopically.

2015
Stoichko D Dimitrov Scot Wheeler Dorota Niedzialek Bob C Schroeder Hendrik Utzat Jarvist M Frost Jizhong Yao Alexander Gillett Pabitra S Tuladhar Iain McCulloch Jenny Nelson James R Durrant

Electron spin is a key consideration for the function of organic semiconductors in light-emitting diodes and solar cells, as well as spintronic applications relying on organic magnetoresistance. A mechanism for triplet excited state generation in such systems is by recombination of electron-hole pairs. However, the exact charge recombination mechanism, whether geminate or nongeminate and whethe...

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