Charge carrier dynamics

The electron drift velocity in solid Ar, Kr, and Xe was measured by Miller et al. (1968). Thin-crystal specimens of 50 to 500 pm thickness were grown from the liquid. Excess charge carriers were injected from a thin layer of ionization produced by an electron beam at the surface of the sample. Measurements in solid neon were performed with photoelectrons injected from a semitransparent cathode (Sakai et al., 1982). In this case, the measurement could not be extended to low enough fields to obtain the low field mobility. Here the drift velocities were extrapolated assuming v proportional 

Chapter 7 and for the positive ions, the activation is approximately equal to the activation energy of the vacancy-assisted diffusion process of the atoms. For the diffusion of the negative ions an activation energy was measured which is larger by 25 to 50% than that of the atomic diffusion process. The structure of the negative ion is that of an electron residing in a cavity the same way as in the liquid (see Section 7.2). The positive ion in solid helium probably consists of an ionic core formed by (He+)He or (He+)He2 surrounded by a deformed lattice due to the influence of electrostriction. 

Electrons were found to become localized on the surface of solid hydrogen (Troyanovskii and Khaikin, 1981). As in the case of electrons on a liquid helium surface, the electrons absorb electromagnetic radiation in the GHz range (Edelman and Faley, 1983). Also on the surface of sNe a two-dimensional electron system was observed (Kajita, 1984). 

Electron and hole mobilities were measured in solid N2, O2, and CO (Loveland et al., 1972). The carrier mobilities are in the range of 10 to lO cm V s and they 

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Gelinck GH, Warman JM (1996) Charge carrier dynamics in pulse-irradiated polyphenyle-nevinylenes effects of broken conjugation, temperature, and accumulated dose. J Phys Chem 100 20035... 

Schouten PG (1994) Charge carrier dynamics in pulse-irradiated columnar aggregates of mesomorphic porphyrins and phthalocyanines. Delft University of Technology, The Netherlands. ISBN 90-73861-22-5 (available from Warman JM on request)... 

Morgan, J. R. Natarajan, L. V. Picosecond transient grating study of charge carrier dynamics in colloidal cadmium sulfide, J. Phys. Chem. 1989, 93, 5. 

Cavaleri, J. J. Skinner, D. E. Colombo, D. P. J. Bowman, R. M. Femtosecond study of the size-dependent charge carrier dynamics in ZnO nanocluster solutions, J. Phys. Chem. 1995, 103, 5378. 

Bitterling, K. Willig, F. Charge carrier dynamics in the picosecond time domain in photoelectrochemical cells, J. Electroanal. Chem. Interfacial Electrochem. 1986, 204, 211. 

Fitzmaurice, D. Frei, H. Rabani, J. Time-resolved optical study on the charge carrier dynamics in a TiO Agl sandwich colloid, J. Phys. Chem. 1995, 99, 9176. 

Thus, it can be seen that a study of the steady state photoelectrochemistry of colloidal semiconductors with the ORDE can provide information relating to the energy distribution of the particle surface states, the photogenerated carrier density and the quantum efficiency of carrier generation. The next section describes how to obtain information pertaining to intraparticle charge carrier dynamics from a study of the behaviour of transient photocurrents at the ORDE. 

Bahnemann, D.W., M. Hilgendorff and R. Memming (1997). Charge carrier dynamics at Ti02 particles Reactivity of free and trapped holes. Journal of Physical Chemistry B, 101(21), 4265 1275. 

Quist PAC, Savenije TJ, Koetse MM, Veenstra SC, Kroon JM, Siebbeles LDA (2005) The effect of annealing on the charge-carrier dynamics in a polymer/polymer bulk heterojunction for photovoltaic applications. Adv Funct Mater 15 469... 

TA It will give a reaction up to femto to the microsecond. Effective tool for unravelling at the kinetics of a single step from the subsequent reaction steps under relevant reaction conditions and probing the charge carrier dynamics and lifetimes. Ultrafast TA was used for probing the hole transfer kinetics. 

Savenije, T.J. et ah. The effect of thermal treatment on the morphology and charge carrier dynamics in a polythiophene-fullerene bulk heterojunction, Adv. Fund. Mater. 15, 1260-1266, 2005. 

Future work on these unique particles, which may act as prototypic structures for investigations of semiconductor boundaries, inner surfaces, and charge carrier separation and localization, will include the systematic study of temperature-dependent charge carrier dynamics as a function of the composition of the particles as well as experiments with materials other than CdS and HgS. It is believed that the preparative approach should be of more generality, possibly yielding particles consisting of more than one well and/or more than two materials. 

Underwood, D. E, Kippeny, T. and Rosenthal, S. J. (2001) Charge Carrier Dynamics in CdSe nanocrystals Implications for the Use of Qnantum Dots in Novel Photovoltaics. The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics, 16,241-244. 

Zhang, J. Z. (2000) Interfacial Charge Carrier Dynamics of Colloidal Semicondnctor Nanoparticles. J. Phys. Chem. B, 104,7239-53. 

A. Pecchia, O.R. Lozman, B. Movaghar, N. Boden, R.J. Bushby, Photoconductive transients and one-dimentional charge carrier dynamics in discotic liquid crystals. Phys. Rev. B 65, 104204-1-10 (2002)... 

A. Saeki, S. Seki, T. Sunagawa, K. Ushida, S. Tagawa, Charge-carrier dynamics in polythiophene films studied by in situ measurement of flash-photolysis time-resolved microwave conductivity (FP-TRMC) and transient optical spectroscopy (TOS). Philos. Mag. 86, 1261-1276 (2006)... 

Wheeler D. A., Wang G., Ling Y, Li Y. and Zhang J. Z. (2012). Nanostmctured hematite synthesis, characterization, charge carrier dynamics, and photoelectrochemical properties. Energy Environmental Science, 5(5), 6682-6702. 

Tang, J.W. Durrant, J.R. and King, D.R. Mechanism of photocatalytic water splitting in Ti02. Reaction of water with photoholes, importance of charge carrier dynamics, and evidence for four-hole chemistry. Journal of the American Chemical Society, 2008. 130(42) p. 13885-13891. 

Underwood DF, Kippeny T, Rosenthal SJ (2001) Charge carrier dynamics in CdSe nanocrystals implications for the use of quantum dots in novel photovoltaics. Eur Phys J D 16 241-244... 

To deal with ET in organic semiconductors, one has to incorporate the coherent motion of electron in the multi-states. The single two-state rate model developed for the donor-acceptor system may not be used straightforwardly. Here, we display a time-dependent wavepacket diffusion (TDWPD) approach for the charge carrier dynamics. In the approach, the nuclear vibrational motions are dealt with the semi-classical fluctuations on the electronic energies of molecules. In this way, we can apply the approach to the nanoscale organic crystals. 

Once the time-dependent Hamiltonian elements are constructed, the charge carrier dynamics can be obtained by solving the Schrodinger equation ... 

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