scholarly journals Electrical Characterization and Modeling of a Gelatin/Graphene System

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Giovanni Landi ◽  
Andrea Sorrentino ◽  
Salvatore Iannace ◽  
Heinrich C. Neitzert
Keyword(s):  
Electrical Impedance ◽  
Open Circuit Voltage ◽  
Series Resistance ◽  
Forward Bias ◽  
Electrical Characterization ◽  
Reaction Rates ◽  
Open Circuit ◽  
Charge Carriers ◽  
Low Frequencies ◽  
Multiple Step

A gelatin/graphene composite has been analyzed by means of current density-voltage and the electrical impedance measurements. The DC electrical behavior has been interpreted in terms of an equivalent Thévenin model taking into account the open circuit voltage and the series resistance. A model based on the effect of the electrical double layer and on the diffusion of the charge carriers is used for the analysis of the experimental data, obtained in the frequency domain. The model reveals for any applied voltages a marked diffusion process at low frequencies. In particular, where the charge transfer mechanism is dominant, the time distribution of the reaction rates reveals that several multiple step reactions occur in the materials, especially at high values of the applied forward bias voltages.

scholarly journals Impedance Spectroscopic Investigation of the Degraded Dye-Sensitized Solar Cell due to Ageing

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Parth Bhatt ◽  
Kavita Pandey ◽  
Pankaj Yadav ◽  
Brijesh Tripathi ◽  
Manoj Kumar
Keyword(s):  
Current Density ◽  
Open Circuit Voltage ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Electrical Characterization ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Conduction Band Edge ◽  
Dye Sensitized

This paper investigates the effect of ageing on the performance of dye-sensitized solar cells (DSCs). The electrical characterization of fresh and degraded DSCs is done under AM1.5G spectrum and the current density-voltage (J-V) characteristics are analyzed. Short circuit current density (JSC) decreases significantly whereas a noticeable increase in open circuit voltage is observed. These results have been further investigated electroanalytically using electrochemical impedance spectroscopy (EIS). An increase in net resistance results in a lower JSC for the degraded DSC. This decrease in current is mainly due to degradation of TiO2-dye interface, which is observed from light and dark J-V characteristics and is further confirmed by EIS measurements. A reduction in the chemical capacitance of the degraded DSC is observed, which is responsible for the shifting of Fermi level with respect to conduction band edge that further results in an increase of open circuit voltage for the degraded DSC. It is also confirmed from EIS that the degradation leads to a better contact formation between the electrolyte and Pt electrode, which improves the fill factor of the DSC. But the recombination throughout the DSC is found to increase along with degradation. This study suggests that the DSC should be used under low illumination conditions and around room temperature for a longer life.

Study of a-Si:H / c-Si Heterojunctions for PV Applications

1996 ◽  
Vol 420 ◽  
Author(s):  
F. Zignani ◽  
R. Galloni ◽  
R. Rizzoli ◽  
M. Ruth ◽  
C. Summonte ◽  
...  
Keyword(s):  
Gas Phase ◽  
Open Circuit Voltage ◽  
Accurate Determination ◽  
Electrical Characterization ◽  
Silicon Layer ◽  
Open Circuit ◽  
Hydrogen Dilution ◽  
Intrinsic Efficiency

Abstracta-Si:H / c-Si heterojunction diodes were produced by PECVD with varying amorphous silicon layer thickness and hydrogen dilution of the gas phase. An accurate determination of the growth rate also in the initial stages of the deposition was made possible by an original chemical method based on the dissolution of the films followed by spectroscopical analysis of the obtained solution.The electrical characterization of the diodes confirms the generation - recombination - multitunneling nature of the transport. Although H2 dilution is important, however, beyond a certain level it is detrimental for the junction quality, probably due to the transition to a microcrystalline phase deposition. Solar cells were also produced, the best results being an open circuit voltage of 610 mV and an intrinsic efficiency of 14.2%.

scholarly journals The Effects of Interdot Spacing and Dot Size on the Performance of InGaAs/GaAs QDIBSC

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Sayeda Anika Amin ◽  
Md. Tanvir Hasan ◽  
Muhammad Shaffatul Islam
Keyword(s):  
Open Circuit Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Charge Carriers ◽  
Electron Wave ◽  
Intermediate Band ◽  
Intermediate Band Solar Cells ◽  
Device Efficiency

In0.53Ga0.47As/GaAs-based quantum dot intermediate band solar cells (QDIBSCs) have been designed and optimized for the next generation photovoltaic technology. The wave behavior of charge carriers inside the dot and their barrier have been analyzed with different dot sizes and interdot spacing. The device characteristics such as short circuit current density, Jsc, open circuit voltage, Voc, and conversion efficiency, η, have been evaluated. Based on the behavior of electron wave function, it is found that varying the dot spacing leads to a change in the IB width and in the density of states, whereas varying the size of dots leads to a formation of a second IB. For a fixed dot spacing, two ranges of dot sizes vary the number of IBs in In0.53Ga0.47As/GaAs QDIBSC. Smaller dots of a size ranging from 2 nm to 5 nm form a single IB while larger dots of a size ranging from 6 nm to 9 nm can produce 2 IBs. The efficiency of 2 IBs close to 1 IB suggests that formation of multiple IBs can possibly enhance the device efficiency.

scholarly journals Effects of Hole-Collecting Buffer Layers and Electrodes on the Performance of Flexible Plastic Organic Photovoltaics

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Sungho Woo ◽  
Hong-Kun Lyu ◽  
Yoon Soo Han ◽  
Youngkyoo Kim
Keyword(s):  
Indium Tin Oxide ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Series Resistance ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Buffer Layers ◽  
Large Area

Here we report the influences of the sheet resistance (Rsheet) of a hole-collecting electrode (indium tin oxide, ITO) and the conductivity of a hole-collecting buffer layer (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT:PSS) on the device performance of flexible plastic organic photovoltaic (OPV) devices. The series resistance (RS) of OPV devices steeply increases with increasingRsheetof the ITO electrode, which leads to a significant decrease of short-circuit current density (JSC) and fill factor (FF) and power conversion efficiency, while the open-circuit voltage (VOC) was almost constant. By applying high-conductivity PEDOT:PSS, the efficiency of OPV devices with highRsheetvalues of 160 Ω/□ and 510 Ω/□ is greatly improved, by a factor of 3.5 and 6.5, respectively. These results indicate that the conductivities of ITO and PEDOT:PSS will become more important to consider for manufacturing large-area flexible plastic OPV modules.

Surface-charge accumulation effects on open-circuit voltage in organic solar cells based on photoinduced impedance analysis

2014 ◽  
Vol 16 (10) ◽  
pp. 4971-4976 ◽  
Author(s):  
Huidong Zang ◽  
Yu-Che Hsiao ◽  
Bin Hu
Keyword(s):  
Solar Cells ◽  
Surface Charge ◽  
Organic Solar Cells ◽  
Open Circuit Voltage ◽  
Impedance Analysis ◽  
Open Circuit ◽  
Charge Carriers ◽  
Charge Accumulation

The accumulation of dissociated charge carriers plays an important role in reducing the loss occurring in organic solar cells.

Anisotropic Transport in Microcrystalline P-I-N Devices

1999 ◽  
Vol 557 ◽  
Author(s):  
M. Vieira ◽  
A. Fantoni ◽  
M. Fernandes ◽  
A. Maçarico ◽  
I. Martins ◽  
...  
Keyword(s):  
Near Infrared ◽  
Open Circuit Voltage ◽  
Spectral Response ◽  
Forward Bias ◽  
Infrared Region ◽  
Open Circuit ◽  
Local Fields ◽  
Two Phase ◽  
Enhanced Sensitivity ◽  
Percolation Path

AbstractEntirely μc-Si:H p-i-n structures presenting an enhanced sensitivity to the near infrared region and a positive spectral response under forward bias higher than the open circuit voltage are analysed under different external voltage bias and illumination conditions.A two phase model to explain the transport properties is proposed using as input parameters the measured experimental data. The results suggest that the transport is preferentially concentrated inside the crystalline grains. The conduction within the amorphous regions is poor. The percolation path is different for electrons and holes and is determined by the local fields at the boundaries. These local fields are independent of the externally applied condition, and they can be related to the persistence of the small photocurrent observed when a bias voltage higher than the open circuit voltage is applied.

Effects of Silicon:Carbon P+ Layer Interfaces on Solar Cells

1987 ◽  
Vol 95 ◽  
Author(s):  
F. R. Jeffrey ◽  
G. D. Vernstrom ◽  
M. F. Weber ◽  
J. R. Gilbert
Keyword(s):  
Open Circuit Voltage ◽  
Series Resistance ◽  
Photovoltaic Performance ◽  
Transparent Conductive Oxide ◽  
Open Circuit ◽  
Electron Current ◽  
Potential Source ◽  
Conductive Oxide ◽  
Abrupt Interface ◽  
High Series

AbstractResults are presented showing the effects on amorphous silicon (a-Si) photovoltaic performance of the interfaces associated with a silicon carbide (a-Si:C) p+ layer. Carbon grading into the intrinsic layer from the p+ layer increases open circuit voltage (Voc) from O.7V to 0.88V. This effect is very similar to the boron profile effect reported earlier and supports the contention that Voc is being limited by an electron current at the p-i interface. The interface between the p+ a-Si:C layer and the transparent conductive oxide (TCO) is shown to be a potential source of high series resistance, with an abrupt interface showing the most serious problem. The effect is explained by electron injection from the TCO into the p+ layer being inhibited as a result of band mismatch.

scholarly journals Behaviour of PV cell with variation in parameters

2018 ◽  
Vol 3 (1) ◽  
pp. 11-13
Author(s):  
P. V. Ram Kumar ◽  
◽  
Aman Khurana ◽  
R. S. Mishra
Keyword(s):  
Open Circuit Voltage ◽  
Series Resistance ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Temperature Series ◽  
Saturation Current ◽  
Electrical Behavior ◽  
Uniform Illumination ◽  
Shunt Resistance

First electrical behavior i.e. short circuit current and open-circuit voltage is observed. The effect of different parameters on the I-V and P-V curve is studied considering uniform illumination. These parameters are insolation level, temperature, series resistance, shunt resistance, diode reverse saturation current. A variation on I-V and P-V curves are different with each parameter. With some parameters, the effect is significant while for others the effect is not so significant. For the parameters whose effect is not so significant large variation of inputs is taken for showing the effect. Simulation work is done in MATLAB

Sign in / Sign up

Export Citation Format

Share Document