Charge mobility determination by current extraction under linear increasing voltages: Case of nonequilibrium charges and field-dependent mobilities

Bange, Sebastian; Schubert, Marcel; Neher, Dieter

doi:10.1103/physrevb.81.035209

Cited by 68 publications

(71 citation statements)

References 23 publications

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“…90 We can see from the figure that eq 14 gives mobility closer to the correct value than the original expression does.…”

Section: Reviewmentioning

confidence: 72%

“…These effects may give significant errors under certain conditions. 90 Dennler et al reported the determination of hole mobilities in blend films of PCBM and a PPV derivative. 95 96 The nature of the transient peaks was correlated with the fill factor of the BHJSCs, and it was reported that for the blend films with balanced hole and electron mobilities highest fill factors were obtained.…”

Section: Reviewmentioning

confidence: 99%

See 1 more Smart Citation

Techniques for characterization of charge carrier mobility in organic semiconductors

Kokil

Yang

Kumar

2012

J Polym Sci B Polym Phys

149

128

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The charge transport characteristics of organic semiconductors are one of the key attributes that impacts the performance of organic electronic and optoelectronic devices in which they are utilized. For improved performance in organic photovoltaic cells, light-emitting diodes, and field-effect transistors (FETs), efficient transport of the charge carriers within the organic semiconductor is especially critical. Characterization of charge transport in these organic semiconductors is important both from scientific and technological perspectives. In this review, we shall mainly discuss the techniques for measuring the charge carrier mobility and not the theoretical underpinnings of the mechanism of charge transport. Mobility measurements in organic semiconductors and particularly in conjugated polymers, using space-charge-limited current, time of flight, carrier extraction by linearly increasing voltage, double injection, FETs, and impedance spectroscopy are discussed. The relative merits, as well as limitations for each of these techniques are reviewed.

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“…90 We can see from the figure that eq 14 gives mobility closer to the correct value than the original expression does.…”

Section: Reviewmentioning

confidence: 72%

Section: Reviewmentioning

confidence: 99%

Techniques for characterization of charge carrier mobility in organic semiconductors

Kokil

Yang

Kumar

2012

J Polym Sci B Polym Phys

149

128

View full text Add to dashboard Cite

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“…Disadvantages of the CELIV method are the following: in disordered materials the charge carrier mobility usually depends on the electric field strength, but in the CELIV method the electric field is increasing with time, so the charge carrier mobility, that is calculated from the measured t max , is determined at E = At max /d with an error [8]; it is not clear what mobility and of which charge carriers is determined. If the densities of charge carriers are comparable, the current maxima of holes and electrons separate when the ratio of charge carrier mobility is greater than 3.…”

Section: Methods and Their Applicationsmentioning

confidence: 99%

Charge carrier transport and recombination in disordered materials

Juška¹,

Arlauskas²,

Genevičius³

2016

Lith. J. Phys.

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In this brief review the methods for investigation of charge carrier transport and recombination in thin layers of disordered materials and the obtained results are discussed. The method of charge carrier extraction by linearly increasing voltage (CELIV) is useful for the determination of mobility, bulk conductivity and density of equilibrium charge carriers. The extraction of photogenerated charge carriers (photo-CELIV) allows one to independently investigate relaxation of both the mobility and density of photogenerated charge carriers. The extraction of injected charge carriers (i-CELIV) is effective for the independent investigation of transport peculiarities of both injected holes and electrons in bulk heterojunctions. For the investigation of charge carrier recombination we proposed integral time-of-flight (TOF) and double-injection (DI) current transient methods. The methods allowed us to obtain the following significant results: to determine the reason of the conductivity dependence on electric field strength and temperature in the amorphous and microcrystalline hydrogenated silicon and π-conjugated polymers, the time dependent Langevin recombination, the impact of morphology on charge carrier mobility, the reason of reduced Langevin recombination in RR-PHT (regioregular poly(3-hexylthiophene))/PCBM (1-(3-methoxycarbonyl)propyl-1phenyl-[6,6]-methanofullerene) bulk heterojunction structures -2D Langevin recombination; and to evaluate that the mobility of holes is predetermined by off-diagonal dispersion in poly-PbO.

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“…For instance, in the fields of dye-sensitized solar cells and organic photovoltaics (OPVs) [2,9,10], substantial insights on recombination and charge transport are gained by examining photocurrent, photovoltage, and charge-extraction transients of planar diode devices [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. In terms of specific analysis, examination of the temporal decay of photocurrent transients has been used to measure the chargetransport properties of organic semiconductors [26][27][28], while the integral of these transients has been taken to quantify initial amounts of photogenerated charge [29][30][31]. Additionally, charge-extraction transients are routinely used to probe semiconductor recombination kinetics, average doping densities, and carrier mobilities [32][33][34][35][36][37].…”

Section: Introductionmentioning

confidence: 99%

Theory of Current Transients in Planar Semiconductor Devices: Insights and Applications to Organic Solar Cells

2015

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Time-domain current measurements are widely used to characterize semiconductor material properties, such as carrier mobility, doping concentration, carrier lifetime, and the static dielectric constant. It is therefore critical that these measurements be theoretically understood if they are to be successfully applied to assess the properties of materials and devices. In this paper, we derive generalized relations for describing current-density transients in planar semiconductor devices at uniform temperature. By spatially averaging the charge densities inside the semiconductor, we are able to provide a rigorous, straightforward, and experimentally relevant way to interpret these measurements. The formalism details several subtle aspects of current transients, including how the electrode charge relates to applied bias and internal space charge, how the displacement current can alter the apparent free-carrier current, and how to understand the integral of a charge-extraction transient. We also demonstrate how the formalism can be employed to derive the current transients arising from simple physical models, like those used to describe charge extraction by linearly increasing voltage (CELIV) and time-of-flight experiments. In doing so, we find that there is a nonintuitive factor-of-2 reduction in the apparent free-carrier concentration that can be easily missed, for example, in the application of charge-extraction models. Finally, to validate our theory and better understand the different current contributions, we perform a full time-domain drift-diffusion simulation of a CELIV trace and compare the results to our formalism. As expected, our analytic equations match precisely with the numerical solutions to the drift-diffusion, Poisson, and continuity equations. Thus, overall, our formalism provides a straightforward and general way to think about how the internal space-charge distribution, the electrode charge, and the externally applied bias translate into a measured current transient in a planar semiconductor device.

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Charge mobility determination by current extraction under linear increasing voltages: Case of nonequilibrium charges and field-dependent mobilities

Cited by 68 publications

References 23 publications

Techniques for characterization of charge carrier mobility in organic semiconductors

Techniques for characterization of charge carrier mobility in organic semiconductors

Charge carrier transport and recombination in disordered materials

Theory of Current Transients in Planar Semiconductor Devices: Insights and Applications to Organic Solar Cells

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