scholarly journals Light Intensity-dependent Variation in Defect Contributions to Charge Transport and Recombination in a Planar MAPbI3 Perovskite Solar Cell

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shinyoung Ryu ◽  
Duc Cuong Nguyen ◽  
Na Young Ha ◽  
Hui Joon Park ◽  
Y. H. Ahn ◽  
...  
Keyword(s):  
Solar Cell ◽  
Ideality Factor ◽  
Internal Quantum Efficiency ◽  
Intensity Variation ◽  
Charge Trapping ◽  
Equation Model ◽  
Open Circuit ◽  
Equivalent Circuit Analysis ◽  
Intensity Dependence ◽  
Bimolecular Recombination

AbstractWe investigated operation of a planar MAPbI3 solar cell with respect to intensity variation ranging from 0.01 to 1 sun. Measured J-V curves consisted of space-charge-limited currents (SCLC) in a drift-dominant range and diode-like currents in a diffusion-dominant range. The variation of power-law exponent of SCLC showed that charge trapping by defects diminished as intensity increased, and that drift currents became eventually almost ohmic. Diode-like currents were analysed using a modified Shockley-equation model, the validity of which was confirmed by comparing measured and estimated open-circuit voltages. Intensity dependence of ideality factor led us to the conclusion that there were two other types of defects that contributed mostly as recombination centers. At low intensities, monomolecular recombination occurred due to one of these defects in addition to bimolecular recombination to result in the ideality factor of ~1.7. However, at high intensities, another type of defect not only took over monomolecular recombination, but also dominated bimolecular recombination to result in the ideality factor of ~2.0. These ideality-factor values were consistent with those representing the intensity dependence of loss-current ratio estimated by using a constant internal-quantum-efficiency approximation. The presence of multiple types of defects was corroborated by findings from equivalent-circuit analysis of impedance spectra.

Design and modeling of an SJ infrared solar cell approaching upper limit of theoretical efficiency

2018 ◽  
Vol 32 (02) ◽  
pp. 1850014 ◽  
Author(s):  
G. S. Sahoo ◽  
G. P. Mishra
Keyword(s):  
Solar Cell ◽  
Quantum Efficiency ◽  
Conversion Efficiency ◽  
Internal Quantum Efficiency ◽  
Spectral Response ◽  
Short Circuit ◽  
Cost Effective ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit

Recent trends of photovoltaics account for the conversion efficiency limit making them more cost effective. To achieve this we have to leave the golden era of silicon cell and make a path towards III–V compound semiconductor groups to take advantages like bandgap engineering by alloying these compounds. In this work we have used a low bandgap GaSb material and designed a single junction (SJ) cell with a conversion efficiency of 32.98%. SILVACO ATLAS TCAD simulator has been used to simulate the proposed model using both Ray Tracing and Transfer Matrix Method (under 1 sun and 1000 sun of AM1.5G spectrum). A detailed analyses of photogeneration rate, spectral response, potential developed, external quantum efficiency (EQE), internal quantum efficiency (IQE), short-circuit current density (J[Formula: see text]), open-circuit voltage (V[Formula: see text]), fill factor (FF) and conversion efficiency ([Formula: see text]) are discussed. The obtained results are compared with previously reported SJ solar cell reports.

scholarly journals Extraction of Saturation Current and Ideality Factor from Measuring Voc and Isc of Photovoltaic Modules

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
E. L. Meyer
Keyword(s):  
Solar Cell ◽  
Ideality Factor ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Outdoor Exposure ◽  
Open Circuit ◽  
Saturation Current ◽  
Easy Method ◽  
Two Parameters

Saturation current (I0) and ideality factor (n) of a p-n junction solar cell are an indication of the quality of the cell. These two parameters are usually estimated from dark current-voltage measurements. In this study, a quick and easy method to determine these two parameters by measuring open-circuit, Voc, and short-circuit current, Isc, is presented. Solar cell designers can use this method as a grading or diagnostic tool to evaluate degradation in photovoltaic (PV) modules. In order to verify the Voc-Isc method, a series of experiments have been conducted on a single cell and a 36-cell module. Good agreement between our Voc-Isc method and dark I-V measurements was obtained. An application of the method on the performance degradation of a single-junction a-Si:H module revealed that the module’s I0 increased by more than three orders of magnitude and n increased by 65% after an outdoor exposure of 130 kWh/m2. This increase in n indicates that after exposure, the recombination current in the cells’ space charge region increased due to the light-induced formation of metastable defects. The method is also used to assess the quality of five PV module technologies and proved to be reliable despite defective cells in a module.

scholarly journals Light intensity dependence of organic solar cell operation and dominance switching between Shockley–Read–Hall and bimolecular recombination losses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shinyoung Ryu ◽  
Na Young Ha ◽  
Y. H. Ahn ◽  
Ji-Yong Park ◽  
Soonil Lee
Keyword(s):  
Solar Cell ◽  
Light Intensity ◽  
Organic Solar Cell ◽  
Defect Density ◽  
Short Circuit ◽  
Open Circuit ◽  
Intensity Increase ◽  
Light Intensities ◽  
Bimolecular Recombination ◽  
Simulation Results

AbstractWe investigated the variation of current density–voltage (J–V) characteristics of an organic solar cell (OSC) in the dark and at 9 different light intensities ranging from 0.01 to 1 sun of the AM1.5G spectrum. All three conventional parameters, short-circuit currents (Jsc), open-circuit voltage (Voc), and Fill factor (FF), representing OSC performance evolved systematically in response to light intensity increase. Unlike Jsc that showed quasi-linear monotonic increase, Voc and FF showed distinctive non-monotonic variations. To elucidate the origin of such variations, we performed extensive simulation studies including Shockley–Read–Hall (SRH) recombination losses. Simulation results were sensitive to defect densities, and simultaneous agreement to 10 measured J–V curves was possible only with the defect density of $$5 \times 10^{12} {\text{ cm}}^{ - 3}$$ 5 × 10 12 cm - 3 . Based on analyses of simulation results, we were able to separate current losses into SRH- and bimolecular-recombination components and, moreover, identify that the competition between SRH- and bimolecular-loss currents were responsible for the aforementioned variations in Jsc, Voc, and FF. In particular, we verified that apparent demarcation in Voc, and FF variations, which seemed to appear at different light intensities, originated from the same mechanism of dominance switching between recombination losses.

The Mechanism for Defect Generation Studied by Photodegradation of A-Si:H Solar Cells Under Electrical Bias

1992 ◽  
Vol 258 ◽  
Author(s):  
Liyou Yang ◽  
L. Chen ◽  
J.Y. Hou ◽  
Y.M. Li
Keyword(s):  
Experimental Data ◽  
Solar Cells ◽  
Open Circuit ◽  
Recombination Mechanism ◽  
Free Hole ◽  
Intensity Dependence ◽  
Bimolecular Recombination ◽  
Electrical Bias ◽  
Trapped Electron ◽  
Open Circuit Condition

ABSTRACTThe light induced degradation of a-Si:H p-i-n solar cells under electrical bias has been systematically studied. By comparing the results with the light intensity dependence of cell degradation under open circuit condition, we show that the only recombination mechanism, which can be consistent with the experimental data in both cases, is based on the bimolecular recombination between a free hole and a trapped electron at the “weak” bond site. Other possibilities for defect creation are also pointed out.

Efficiency Enhancement in Hybrid P3HT/Silicon Nanocrystal Solar Cells

Green ◽  
2011 ◽  
Vol 1 (4) ◽  
Author(s):  
Sabrina Niesar ◽  
Wolfgang Fabian ◽  
Nils Petermann ◽  
Daniel Herrmann ◽  
Eberhard Riedle ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Microwave Plasma ◽  
Weight Ratio ◽  
Charge Trapping ◽  
Open Circuit ◽  
Cell Performance ◽  
Strong Impact ◽  
Plasma Synthesis ◽  
Solar Cell Performance

AbstractHybrid organic-inorganic solar cells from poly(3-hexylthiophene) (P3HT) and freestanding silicon nanocrystals (Si-ncs) combine the advantages of silicon-based photovoltaics with the cost-efficient solution processing technique. At present, the microwave-plasma synthesis of Si-ncs that allows for a future upscaling to industrial demands is at the expense of the Si-nc surface quality and the number of charge-trapping defects. Here, we present an enhancement of the solar cell performance by identifying the major factors which are limiting the device efficiency. With the help of low-cost post-growth treatments of the Si-ncs and the optimization of various device parameters, P3HT:Si-ncs bulk heterojunction solar cells with an efficiency up to 1.1% are achieved. In particular, etching of the Si-ncs with hydrofluoric acid to remove the surface oxide shells and surface defects has a strong impact on the solar cell performance. An intermediate Si weight ratio of around 60% is found to lead to the highest current densities. For Si-ncs with very small diameters, an additional enhancement of the open circuit voltage was observed. Moreover, we show that the structural order of P3HT has a strong influence on the efficiency, which can be explained by an improved charge carrier separation at the P3HT/Si-ncs interface in combination with an enhanced charge transport in the P3HT phase.

Use of Transparent Conductive Oxide Materials with Low Indices of Refraction in Amorphous Silicon-Based Solar Cell Technology

2005 ◽  
Vol 862 ◽  
Author(s):  
Scott J. Jones ◽  
Joachim Doehler ◽  
Tongyu Liu ◽  
David Tsu ◽  
Jeff Steele ◽  
...  
Keyword(s):  
Solar Cell ◽  
Amorphous Silicon ◽  
Transparent Conductive Oxide ◽  
Open Circuit ◽  
Long Term Stability ◽  
Back Reflectors ◽  
Stability Issues ◽  
Silicon Based ◽  
Solar Cell Technology

AbstractNew types of transparent conductive oxides with low indices of refraction have been developed for use in optical stacks for the amorphous silicon (a-Si) solar cell and other thin film applications. The alloys are ZnO based with Si and MgF added to reduce the index of the materials through the creation of SiO2 or MgF2, with n=1.3-1.4, or the addition of voids in the materials. Alloys with 12-14% Si or Mg have indices of refraction at λ=800nm between 1.6 and 1.7. These materials are presently being used in optical stacks to enhance light scattering by Al/multi-layer/ZnO back reflectors in a-Si based solar cells to increase light absorption in the semiconductor layers and increase open circuit currents and boost device efficiencies. In contrast to Ag/ZnO back reflectors which have long term stability issues due to electromigration of Ag, these Al based back reflectors should be stable and usable in manufactured PV products. In this manuscript, structural properties for the materials will be reported as well as the performance of solar cell devices made using these new types of materials.

Additive-induced Miscibility Regulation and Hierarchical Morphology Enables 17.5% Binary Organic Solar Cells

2021 ◽  
Author(s):  
Jie Lv ◽  
Hua Tang ◽  
Jiaming Huang ◽  
Cenqi Yan ◽  
Kuan Liu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Organic Solar Cells ◽  
Organic Solar Cell ◽  
Power Conversion ◽  
Charge Trapping ◽  
Free Charge ◽  
Charge Generation ◽  
Low Charge ◽  
Hierarchical Morphology

Due to the barrierless free charge generation, low charge trapping, and high charge mobilities, the PM6:Y6 organic solar cell (OSC) achieves excellent power conversion efficiency (PCE) of 15.7%. However, the...

scholarly journals Numerical Simulation Analysis of Ag Crystallite Effects on Interface of Front Metal and Silicon in the PERC Solar Cell

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 592
Author(s):  
Myeong Sang Jeong ◽  
Yonghwan Lee ◽  
Ka-Hyun Kim ◽  
Sungjin Choi ◽  
Min Gu Kang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Surface Recombination ◽  
Open Circuit ◽  
Surface Recombination Velocity ◽  
Metal Interface ◽  
Ag Crystallites ◽  
Recombination Velocity

In the fabrication of crystalline silicon solar cells, the contact properties between the front metal electrode and silicon are one of the most important parameters for achieving high-efficiency, as it is an integral element in the formation of solar cell electrodes. This entails an increase in the surface recombination velocity and a drop in the open-circuit voltage of the solar cell; hence, controlling the recombination velocity at the metal-silicon interface becomes a critical factor in the process. In this study, the distribution of Ag crystallites formed on the silicon-metal interface, the surface recombination velocity in the silicon-metal interface and the resulting changes in the performance of the Passivated Emitter and Rear Contact (PERC) solar cells were analyzed by controlling the firing temperature. The Ag crystallite distribution gradually increased corresponding to a firing temperature increase from 850 ∘C to 950 ∘C. The surface recombination velocity at the silicon-metal interface increased from 353 to 599 cm/s and the open-circuit voltage of the PERC solar cell decreased from 659.7 to 647 mV. Technology Computer-Aided Design (TCAD) simulation was used for detailed analysis on the effect of the surface recombination velocity at the silicon-metal interface on the PERC solar cell performance. Simulations showed that the increase in the distribution of Ag crystallites and surface recombination velocity at the silicon-metal interface played an important role in the decrease of open-circuit voltage of the PERC solar cell at temperatures of 850–900 ∘C, whereas the damage caused by the emitter over fire was determined as the main cause of the voltage drop at 950 ∘C. These results are expected to serve as a steppingstone for further research on improvement in the silicon-metal interface properties of silicon-based solar cells and investigation on high-efficiency solar cells.

scholarly journals CdTe-Based Thin Film Solar Cells: Past, Present and Future

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1684
Author(s):  
Alessandro Romeo ◽  
Elisa Artegiani
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Early Years ◽  
Solar Cell Efficiency ◽  
Cell Efficiency

CdTe is a very robust and chemically stable material and for this reason its related solar cell thin film photovoltaic technology is now the only thin film technology in the first 10 top producers in the world. CdTe has an optimum band gap for the Schockley-Queisser limit and could deliver very high efficiencies as single junction device of more than 32%, with an open circuit voltage of 1 V and a short circuit current density exceeding 30 mA/cm2. CdTe solar cells were introduced at the beginning of the 70s and they have been studied and implemented particularly in the last 30 years. The strong improvement in efficiency in the last 5 years was obtained by a new redesign of the CdTe solar cell device reaching a single solar cell efficiency of 22.1% and a module efficiency of 19%. In this paper we describe the fabrication process following the history of the solar cell as it was developed in the early years up to the latest development and changes. Moreover the paper also presents future possible alternative absorbers and discusses the only apparently controversial environmental impacts of this fantastic technology.

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