Titanium oxide nanoparticle increases shallow traps to suppress space charge accumulation in polypropylene dielectrics

RSC Advances ◽  
2016 ◽  
Vol 6 (54) ◽  
pp. 48720-48727 ◽  
Author(s):  
Yao Zhou ◽  
Jun Hu ◽  
Bin Dang ◽  
Jinliang He
Keyword(s):  
Charge Carrier ◽  
Space Charge ◽  
Titanium Oxide ◽  
Carrier Mobility ◽  
Charge Carrier Mobility ◽  
Charge Accumulation ◽  
Oxide Nanoparticle ◽  
Surface Modified ◽  
Shallow Traps

Introduction of surface modified nano-TiO2 increases shallow traps and enhances charge carrier mobility so as to suppress space charge accumulation.

scholarly journals Elucidating the Impact of Charge Selective Contact in Halide Perovskite Through Impedance Spectroscopy

2019 ◽  
Author(s):  
Mohd Taukeer Khan ◽  
Manuel Salado ◽  
Abdullah R. D. Almohammedi ◽  
Samrana Kazim ◽  
Shahzada Ahmad
Keyword(s):  
Solar Cells ◽  
Impedance Spectroscopy ◽  
Charge Carrier ◽  
Carrier Mobility ◽  
Short Circuit ◽  
Perovskite Solar Cells ◽  
Charge Carrier Mobility ◽  
Charge Accumulation ◽  
Frequency Dependent ◽  
The Impact

<p>The electron and hole selective contact (SC) play a pivotal role in the performance of perovskite solar cells. In order to separate the interfacial phenomenon from bulk, the influence of charge SC was elucidated, by means of impedance spectroscopy. The specific role played by TiO<sub>2</sub> and <i>Spiro-OMeTAD</i> as electron and hole SC in perovskite solar cells was investigated at short circuit condition at different temperatures. We have probed MAPbI<sub>3</sub> and (FAPbI<sub>3</sub>)<sub>0.85</sub>(MAPbBr<sub>3</sub>)<sub>0.15 </sub>and elucidated parameters such as charge carrier mobility, recombination resistance, time constant and charge carrier kinetics in perovskite layer and at the interface of perovskite/SC. Charge carrier mobility in mixed perovskite was found to be nearly two order of magnitude higher as compared to MAPbI<sub>3</sub>. Moreover, the carrier mobility in devices with only electron SC was found to be higher as compared only hole SC. The charge accumulation at TiO<sub>2</sub>/perovskite/<i>Spiro</i>-OMeTAD interfaces were studied via frequency dependent capacitance, revealing higher charge accumulation at perovskite/S<i>piro</i>-OMeTAD than at TiO<sub>2</sub>/perovskite interface. By performing varying temperature frequency dependent capacitance measurements the distribution of density of state within the bandgap of the perovskites, the emission rate of electrons from the trap states and traps activation energy was determined. </p>

scholarly journals Revealing Charge Carrier Mobility and Defect Densities in Metal Halide Perovskites via Space-Charge-Limited Current Measurements

2021 ◽  
Vol 6 (3) ◽  
pp. 1087-1094 ◽  
Author(s):  
Vincent M. Le Corre ◽  
Elisabeth A. Duijnstee ◽  
Omar El Tambouli ◽  
James M. Ball ◽  
Henry J. Snaith ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Space Charge ◽  
Carrier Mobility ◽  
Charge Carrier Mobility ◽  
Metal Halide ◽  
Space Charge Limited Current ◽  
Limited Current ◽  
Halide Perovskites ◽  
Defect Densities ◽  
Space Charge Limited

scholarly journals Investigation of the Space Charge and DC Breakdown Behavior of XLPE/α-Al2O3 Nanocomposites

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1333
Author(s):  
Xiangjin Guo ◽  
Zhaoliang Xing ◽  
Shiyi Zhao ◽  
Yingchao Cui ◽  
Guochang Li ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Space Charge ◽  
Direct Current ◽  
Breakdown Strength ◽  
Charge Carrier Mobility ◽  
Charge Accumulation ◽  
Polyethylene Matrix ◽  
Uniform Size ◽  
Α Al2o3 ◽  
Surface Modified

This paper describes the effects of α-Al2O3 nanosheets on the direct current voltage breakdown strength and space charge accumulation in crosslinked polyethylene/α-Al2O3 nanocomposites. The α-Al2O3 nanosheets with a uniform size and high aspect ratio were synthesized, surface-modified, and characterized. The α-Al2O3 nanosheets were uniformly distributed into a crosslinked polyethylene matrix by mechanical blending and hot-press crosslinking. Direct current breakdown testing, electrical conductivity tests, and measurements of space charge indicated that the addition of α-Al2O3 nanosheets introduced a large number of deep traps, blocked the charge injection, and decreased the charge carrier mobility, thereby significantly reducing the conductivity (from 3.25 × 10−13 S/m to 1.04 × 10−13 S/m), improving the direct current breakdown strength (from 220 to 320 kV/mm) and suppressing the space charge accumulation in the crosslinked polyethylene matrix. Besides, the results of direct current breakdown testing and electrical conductivity tests also showed that the surface modification of α-Al2O3 nanosheets effectively improved the direct current breakdown strength and reduced the conductivity of crosslinked polyethylene/α-Al2O3 nanocomposites.

Current Conduction in Poly(3-Hexylthiophene) and in Poly(3- Hexylthiophene) doped [6,6]-Phenyl C61-Butyric Acid Methylester Composite Thin Film Devices

2012 ◽  
Vol 67 (10-11) ◽  
pp. 589-600 ◽  
Author(s):  
Zivayi Chiguvare ◽  
Jürgen Parisi
Keyword(s):  
Charge Carrier ◽  
Space Charge ◽  
Transport Properties ◽  
Butyric Acid ◽  
Low Temperatures ◽  
Carrier Mobility ◽  
Short Circuit ◽  
Charge Carrier Mobility ◽  
Current Limit ◽  
Metal Insulator Metal

Transport properties of poly(3-hexylthiophene) (P3HT), and of its blend with [6,6]-phenyl C61- butyric acid methylester (PCBM), were studied by analysing temperature dependent current-voltage characteristics of spin cast thin films sandwiched between aluminium electrodes in a metal-insulator- metal (MIM) configuration. It was found that in Al/P3HT/Al devices, the current is limited by space charge that accumulates near the hole injecting electrode due to the poor bulk transport properties of P3HT. At low temperatures and high applied electric fields the current density obeys a power law of the form J _ Vm, characteristic of space charge limited current (SCLC) in the presence of exponentially distributed traps within the band gap. These traps are filled by charge that is injected by quantum mechanical tunnelling, which is adequately described by the Fowler-Nordheim (FN) theory. By calculating the majority charge carrier mobility in Al/P3HT/Al and Al/P3HT:PCBM/Al devices from the Ohmic, SCLC, and FN tunnelling fits at different temperatures, we have obtained that the charge carrier mobility in P3HT is two orders smaller than the electron mobility in the P3HT:PCBM blend at room temperature, but comparable at low temperatures. This information is important in determining the origin of open circuit voltage and short circuit current limit in solar cells that employ this blend as the active layer.

scholarly journals Elucidating the Impact of Charge Selective Contact in Halide Perovskite Through Impedance Spectroscopy

2019 ◽  
Author(s):  
Mohd Taukeer Khan ◽  
Manuel Salado ◽  
Abdullah R. D. Almohammedi ◽  
Samrana Kazim ◽  
Shahzada Ahmad
Keyword(s):  
Solar Cells ◽  
Impedance Spectroscopy ◽  
Charge Carrier ◽  
Carrier Mobility ◽  
Short Circuit ◽  
Perovskite Solar Cells ◽  
Charge Carrier Mobility ◽  
Charge Accumulation ◽  
Frequency Dependent ◽  
The Impact

<p>The electron and hole selective contact (SC) play a pivotal role in the performance of perovskite solar cells. In order to separate the interfacial phenomenon from bulk, the influence of charge SC was elucidated, by means of impedance spectroscopy. The specific role played by TiO<sub>2</sub> and <i>Spiro-OMeTAD</i> as electron and hole SC in perovskite solar cells was investigated at short circuit condition at different temperatures. We have probed MAPbI<sub>3</sub> and (FAPbI<sub>3</sub>)<sub>0.85</sub>(MAPbBr<sub>3</sub>)<sub>0.15 </sub>and elucidated parameters such as charge carrier mobility, recombination resistance, time constant and charge carrier kinetics in perovskite layer and at the interface of perovskite/SC. Charge carrier mobility in mixed perovskite was found to be nearly two order of magnitude higher as compared to MAPbI<sub>3</sub>. Moreover, the carrier mobility in devices with only electron SC was found to be higher as compared only hole SC. The charge accumulation at TiO<sub>2</sub>/perovskite/<i>Spiro</i>-OMeTAD interfaces were studied via frequency dependent capacitance, revealing higher charge accumulation at perovskite/S<i>piro</i>-OMeTAD than at TiO<sub>2</sub>/perovskite interface. By performing varying temperature frequency dependent capacitance measurements the distribution of density of state within the bandgap of the perovskites, the emission rate of electrons from the trap states and traps activation energy was determined. </p>

The Influence of Nitrogen Position on Charge Carrier Mobility in Enantiopure Aza[6]helicene Crystals

2018 ◽  
Author(s):  
Francesco Salerno ◽  
Beth Rice ◽  
Julia Schmidt ◽  
Matthew J. Fuchter ◽  
Jenny Nelson ◽  
...  
Keyword(s):  
Solid State ◽  
Charge Carrier ◽  
Carrier Mobility ◽  
Chemical Structure ◽  
Crystal Packing ◽  
Charge Carrier Mobility ◽  
Individual Factor ◽  
Charge Mobility ◽  
Order Of Magnitude ◽  
Small Change

<p>The properties of an organic semiconductor are dependent on both the chemical structure of the molecule involved, and how it is arranged in the solid-state. It is challenging to extract the influence of each individual factor, as small changes in the molecular structure often dramatically change the crystal packing and hence solid-state structure. Here, we use calculations to explore the influence of the nitrogen position on the charge mobility of a chiral organic molecule when the crystal packing is kept constant. The transfer integrals for a series of enantiopure aza[6]helicene crystals sharing the same packing were analysed in order to identify the best supramolecular motifs to promote charge carrier mobility. The regioisomers considered differ only in the positioning of the nitrogen atom in the aromatic scaffold. The simulations showed that even this small change in the chemical structure has a strong effect on the charge transport in the crystal, leading to differences in charge mobility of up to one order of magnitude. Some aza[6]helicene isomers that were packed interlocked with each other showed high HOMO-HOMO integrals (up to 70 meV), whilst molecules arranged with translational symmetry generally afforded the highest LUMO-LUMO integrals (40 - 70 meV). As many of the results are not intuitively obvious, a computational approach provides additional insight into the design of new semiconducting organic materials.</p>

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