A physical interpretation of dispersive transport in disordered semiconductors

Tiedje, T.; Rose, Albert

doi:10.1016/0038-1098(81)90886-3

Cited by 729 publications

(252 citation statements)

References 10 publications

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“…͑40͒ is directly related to the classical results on dispersive ͑power-law͒ behavior of the mobility in transient experiments 29 in disordered semiconductors. Figure 4 illustrates the behavior of the trap capacitance as a function of the frequency.…”

Section: ͑36͒mentioning

confidence: 79%

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Beyond the quasistatic approximation: Impedance and capacitance of an exponential distribution of traps

Bisquert

2008

Phys. Rev. B

129

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Electronic carriers in disordered organic and inorganic semiconductor materials, used in electronic, optoelectronic, and photovoltaic devices, are usually affected by an exponential distribution of localized states in the band gap ͑traps͒. In this paper we provide a full solution of the relaxation of carriers in traps of such distribution, as a function of frequency and steady-state Fermi level. This includes in a unified treatment both the quasistatic limit, in which the traps modify time constants such as the trap-limited mobility, and the power-law relaxation at high frequency due to detrapping kinetics. We also analyze the combination of trapping with diffusion transport and recombination dynamics in photovoltaic devices. The different features of impedance and capacitance spectra are interpreted and also the analysis of the spectra in order to derive the main material parameters.

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Section: ͑36͒mentioning

confidence: 79%

“…28,29 Therefore, one can switch from the regime, where the traps remain in equilibrium, to that in which they dominate the transient response. 30 In this paper we provide a full solution of the relaxation of the exponential distribution of traps, which unifies both regimes of behavior in a single framework, in the frequency domain.…”

Section: Introductionmentioning

confidence: 99%

Beyond the quasistatic approximation: Impedance and capacitance of an exponential distribution of traps

Bisquert

2008

Phys. Rev. B

129

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“…The concept of a 'mobility edge' has greatly facilitated our understanding of electronic transport in a disordered system 47 . The mobility edge is a boundary located in the band tail, in which states above it are extended states with band transport, while those below it are localized states that conduct via thermally assisted mechanisms such as Mott variable range hopping (VRH) [48][49][50] or an Arrhenius-type activated behaviour 51 . Four-point variable temperature measurements were performed on our devices from 4.4 to 400 K as shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Electronic transport and device prospects of monolayer molybdenum disulphide grown by chemical vapour deposition

et al. 2014

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Layered transition metal dichalcogenides display a wide range of attractive physical and chemical properties and are potentially important for various device applications. Here we report the electronic transport and device properties of monolayer molybdenum disulphide grown by chemical vapour deposition. We show that these devices have the potential to suppress short channel effects and have high critical breakdown electric field. However, our study reveals that the electronic properties of these devices are at present severely limited by the presence of a significant amount of band tail trapping states. Through capacitance and ac conductance measurements, we systematically quantify the density-of-states and response time of these states. Because of the large amount of trapped charges, the measured effective mobility also leads to a large underestimation of the true band mobility and the potential of the material. Continual engineering efforts on improving the sample quality are needed for its potential applications.

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“…2 and 3, the maximum of the energy histogram E max lies always above and approximately at a constant distance with respect to the Fermi level. If we would assume that E max can be assimilated to the transport energy, this behavior would lead to a constant diffusion coefficient according to eqn (9).…”

Section: Diffusion Coefficient and Transport Energymentioning

confidence: 99%

Random walk numerical simulation for hopping transport at finite carrier concentrations: diffusion coefficient and transport energy concept

Gonzalez-Vazquez

Anta

Bisquert

2009

Phys. Chem. Chem. Phys.

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The random walk numerical simulation (RWNS) method is used to compute diffusion coefficients for hopping transport in a fully disordered medium at finite carrier concentrations. We use Miller-Abrahams jumping rates and an exponential distribution of energies to compute the hopping times in the random walk simulation. The computed diffusion coefficient shows an exponential dependence with respect to Fermi-level and Arrhenius behavior with respect to temperature. This result indicates that there is a well-defined transport level implicit to the system dynamics. To establish the origin of this transport level we construct histograms to monitor the energies of the most visited sites. In addition, we construct ''corrected'' histograms where backward moves are removed. Since these moves do not contribute to transport, these histograms provide a better estimation of the effective transport level energy. The analysis of this concept in connection with the Fermi-level dependence of the diffusion coefficient and the regime of interest for the functioning of dye-sensitised solar cells is thoroughly discussed.

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A physical interpretation of dispersive transport in disordered semiconductors

Cited by 729 publications

References 10 publications

Beyond the quasistatic approximation: Impedance and capacitance of an exponential distribution of traps

Beyond the quasistatic approximation: Impedance and capacitance of an exponential distribution of traps

Electronic transport and device prospects of monolayer molybdenum disulphide grown by chemical vapour deposition

Random walk numerical simulation for hopping transport at finite carrier concentrations: diffusion coefficient and transport energy concept

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