Conventional Photovoltaic Cells Research Articles

Surface Modification of Cellulose Films By Dielectric Barrier Discharge for Organic Photovoltaics Encapsulation

Organic photovoltaics (OPV) are the third generation of solar cells and are more and more attractive for industrial applications. OPV present numerous advantages, such as flexibility, low cost, light weight, large-area production.[1,2] Nonetheless, OPV are not as efficient as the conventional crystalline silicon photovoltaic (PV) cells. Recently, power conversion efficiency (PCE) has reached 18% for OPV, while conventional PV remains around 30% [3]. In this sense, additional works are necessary to improve their processability. Moreover, components of OPV are highly sensitive to water or oxygen, which strongly affect OPV stability in time when used in harsh conditions. Therefore, development of new barrier coatings are today essential to reduce OPV degradation and increase their shelf life. According to the literature, encapsulation can be performed following three strategies: (i) glass-glass encapsulation, (ii) flexible polymer lamination and (iii) thin film direct deposition. Glass-glass encapsulation provides great protection, with good optical properties but it remains fragile and is not compatible with roll-to-roll processes. On the other hand, although, flexible polymer lamination is suitable for roll-to-roll processes, adhesion between the front and back barriers is still complex to deal with, leading sometimes to partial encapsulation, thus increasing OPV degradation. Finally, direct deposition allows to obtain thin films with excellent optical and oxygen and humidity barrier properties. To date, most of thin layers are synthesized under vacuum [1,2]. This work focus on the development new barrier coatings at atmospheric pressure, compatible with roll-to-roll processes using cellulose nanofibrils with excellent oxygen barrier properties [4]. Being hydrophilic, the surface of cellulose nanofibrils have been modified to improve the water barrier properties. Wettability modification (WCA ~ 140°) was successfully achieved with an atmospheric pressure dielectric barrier discharge to control the fragmentation/reticulation of 2,4,6,8-Tetramethylcyclotetrasiloxane (TMCTS).

Influence of Silica Oxide Nanofluid for Different Concentrations on Photovoltaic Cell

Photovoltaic (PV) cells, a renewable fuel, are widely employed. A conventional PV cell also loses efficiency as the temperature rises. This research addresses this issue by cooling the PV cell with nanofluid, specifically SiO2 and distilled water. Applying SiO2 nanofluid experimentally using a real experimental setup is hoped to cool the PV cell’s surface as it becomes heated. This research aims to use distilled water and various concentrations of SiO2 nanofluid, such as 0.1 wt%, 0.2 wt%, and 0.3 wt% on Photovoltaic Cell and flow rate of 2 LPM and a radiation rate of 800 W/m2. ANSYS is used to confirm experimental results by using SiO2 as a nanofluid to lower the PV cell’s temperature and boost its thermal efficiency. The experiment’s findings demonstrated that utilizing nanofluid as a coolant boosted the PV cell’s thermal efficiency and decreased its temperature. Results showed that the thermal efficiency increased with the use of nanofluid as a coolant and with increasing mass concentration. Thermal efficiency values for distilled water, 0.1%, 0.2%, and 0.3% SiO2 were 35.56%, 79.91%, 91.04%, and 104.01%, respectively. This study also discovered that SiO2 works better in terms of cooling the PV cell than normal fluid because of its higher thermal conductivity. The experimental and numerical data show the same decline in PV cell surface temperature and thermal efficiency, unlike the computational results.

Disorder-induced bulk photovoltaic effect in a centrosymmetric van der Waals material

Sunlight is widely seen as one of the most abundant forms of renewable energy, with photovoltaic cells based on pn junctions being the most commonly used platform attempting to harness it. Unlike in conventional photovoltaic cells, the bulk photovoltaic effect (BPVE) allows for the generation of photocurrent and photovoltage in a single material without the need to engineer a pn junction and create a built-in electric field, thus offering a solution that can potentially exceed the Shockley–Queisser efficiency limit. However, it requires a material with no inversion symmetry and is therefore absent in centrosymmetric materials. Here, we demonstrate that breaking the inversion symmetry by structural disorder can induce BPVE in ultrathin PtSe2, a centrosymmetric semiconducting van der Waals material. Homogenous illumination of defective PtSe2 by linearly and circularly polarized light results in a photoresponse termed as linear photogalvanic effect (LPGE) and circular photogalvanic effect (CPGE), which is mostly absent in the pristine crystal. First-principles calculations reveal that LPGE originates from Se vacancies that act as asymmetric scattering centers for the photo-generated electron-hole pairs. Our work emphasizes the importance of defects to induce photovoltaic functionality in centrosymmetric materials and shows how the range of materials suitable for light sensing and energy-harvesting applications can be extended.

Performance investigation of truncated low concentrating photovoltaic-thermal systems with V-trough, compound hyperbolic and compound parabolic concentrators

The electric conversion efficiency of a conventional photovoltaic cell in the market is around 13–22%. The remaining part is converted into heat. It increases the temperature of the photovoltaic cell and decreases the electrical efficiency. In concentrating photovoltaic systems, it comes into prominence. In this study, a comparative performance analysis was carried out among non-imaging concentrating photovoltaic thermal systems with various truncation levels of the reflector to attain uniform illumination and better electrical and thermal energy conversion performance. Compound Parabolic, V-trough, and Compound Hyperbolic concentrators were evaluated in terms of optical performance to decide distinctive truncation levels. The reflector sizes of 72%, 55%, and 42% were considered for evaluating the concentrating photovoltaic-thermal systems. The results show that the truncation reduces the photovoltaic cell temperature and provides more uniform temperature distribution. In the case of Compound Parabolic Concentrator- photovoltaic thermal, the average thermal and electrical power generation decreases by only 0.5% and 1.3% for 28% truncation. Compound parabolic hyperbolic- photovoltaic thermal provided about 45.5% and 21.7% higher average thermal energy generation per unit reflector area compared to V-trough and CPC, respectively. CHC provided about 59.8% and 32.8% higher average electrical power generation per unit reflector area compared to V-trough and CPC, respectively. Truncation reduces the thermal and electrical power generation while the power generation per unit reflector area increases. It indicates that the truncation provides effective use of the reflector. Compound Hyperbolic Photovoltaic Thermal system has the highest power generation per unit reflector area for all truncation levels and incidence angles.

Self-Powered Implantable CMOS Photovoltaic Cell With 18.6% Efficiency

Harvesters for implantable medical applications need to generate enough energy to power their loads, but their efficiency is reduced when implanted under the tissue. Conventional photovoltaic (PV) cell harvesters made with CMOS technology stack cells in series, which raises output voltage but lowers power conversion efficiency. In addition, it is difficult to assess harvester performance prior to fabrication. To address these challenges, we developed a novel parallel PV cell configuration that fully utilizes all triple-well diodes and responds efficiently to near-infrared light. Using an optimized structure, the PV cells were fabricated through standard TSMC 65-nm CMOS technology, achieving an efficiency of 18.6%, open circuit voltage of 0.45 V, and short circuit current of 1.9 mA cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{2}}$ </tex-math></inline-formula> . These results confirm the ability of the device to generate sufficient energy even when implanted beneath the tissue. Multiphysics finite element modeling (FEM) was used to optimize the stacking structure of the CMOS PV cell, and experimental results showed a successfully delivered power density of 1.2 mW cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{2}}$ </tex-math></inline-formula> (single cell 1.04 mm2) when placed 2 mm below porcine skin. Different array configurations of six PV cells were also experimentally studied using external wire switching, demonstrating the flexibility of the PV array in delivering different output energy for various implantable devices.

Electrical and Optical Properties of Boron Doped Zinc Oxide Thin-film Deposited by Metal-organic Chemical Vapour Deposition for Photovoltaic Application

Globally, there is a high demand for clean, sustainable and renewable energy for domestic and industrial use. Conventional photovoltaic cell technology relies heavily on crystalline silicon wafers which render silicon-based solar cells expensive due to the initial cost of production and required complex deposition methods. Due to these challenges, great research interest is now directed towards thin-film solar cells. In this work, the metal-organic chemical vapour deposition (CVD) method was chosen in the preparation of boron-doped zinc oxide (ZnO: B) thin film onto a glass slide substrate. The prepared ZnO: B thin films were characterized and optimized as a window layer for solar light trapping. The transmittance of the ZnO: B films varied between 70% and 81% for boron concentration ranging from 0.0 M to 0.06 M. With the increase in boron concentration, bandgap and resistivity of the ZnO: B varied from 2.96 to 3.72 eV and 120 Ω-cm to 58 Ω-cm, respectively. Based on the results obtained, we believe that ZnO: B is suitable as a window layer for solar light trapping in the fabrication of a photovoltaic cell.

Nanostructured AlGaAsSb Materials for Thermophotovoltaic Solar Cells Applications.

Thermophotovoltaic conversion using heat to generate electricity in photovoltaic cells based on the detraction of thermal radiation suffers from many engineering challenges. The focus of this paper is to study the nanostructure of AlGaAsSb for thermophotovoltaic energy conversion using lattice-matched heterostructures of GaSb-based materials in order to overcome the current challenges. The XAFS spectroscopy technique was used to analyze electronic structures and optical properties of GaSb, (Al, In) GaSbAs. The XAFS spectroscopy analysis showed a powerful decay at peak intensity that reveals to be related to a loss in Sb amount and light As atoms replaced in Sb atoms by 25%. Moreover, it was found that Al/In doped samples have highly symmetric data features (same atomic species substitution). The narrow direct bandgap energy, Eg of Al0.125Ga0.875Sb0.75As0.25 material raised (0.4–0.6 eV) compared to conventional photovoltaic cell bandgap energy (which is generally less than 0.4 eV) with weak absorption coefficients. The thermoelectric properties of AlGaAsSb computed via Botlztrap code showed that the electrons made up the majority of the charge carriers in AlGaAsSb. This nanostructure material exhibited a higher and acceptable figure of merit and demonstrated a promising thermoelectric material for solar thermophotovoltaic applications.

Accurate prophecy of photovoltaic-segmented thermoelectric generator’s performance using a neural network that feeds on finite element-generated data

To further enhance the photovoltaic–thermoelectric system efficiency, this paper proposes a new hybrid system design comprising a segmented thermoelectric generator and aluminum heat sink directly lapped to the back plate of a photovoltaic cell operating under Nigerian transient and fluctuating weather conditions. The performance evaluation and optimization of the hybrid system design is conducted using a numerical model setup in ANSYS software and the optimized parameters include the thermoelectric leg height and cross-sectional area, skutterudite content, ceramic height, fin and fin base heights, convective film coefficient, and solar concentration ratio while the performance indices are the system power generation rate and the system efficiency. Finally, a Bayesian regularized artificial neural network with 10 neurons in the hidden layer is proposed to overcome the lengthy computational time and energy needed to conduct the numerical-inspired system optimization. Results are that the proposed system design improved the efficiency of the conventional photovoltaic cell integrated with regular unsegmented thermoelectric generators by 96% at a solar concentration of 5. Additionally, the numerical-inspired optimization was able to improve the conventional system power output and efficiency by 45.7% and 45.9%, respectively, compared to the unoptimized system when operated under peak sunshine conditions. Finally, the Bayesian regularized neural network with a low mean squared error of 9.7 × 10−14 after 471 iterations and perfect regression correlations for training, testing, and all processes provided a perfect fit of the numerical-generated data, being 201 times faster than the conventional numerical optimization scheme.

A Review of Recent Developments in Preparation Methods for Large-Area Perovskite Solar Cells

The recent rapid development in perovskite solar cells (PSCs) has led to significant research interest due to their notable photovoltaic performance, currently exceeding 25% power conversion efficiency for small-area PSCs. The materials used to fabricate PSCs dominate the current photovoltaic market, especially with the rapid increase in efficiency and performance. The present work reviews recent developments in PSCs’ preparation and fabrication methods, the associated advantages and disadvantages, and methods for improving the efficiency of large-area perovskite films for commercial application. The work is structured in three parts. First is a brief overview of large-area PSCs, followed by a discussion of the preparation methods and methods to improve PSC efficiency, quality, and stability. Envisioned future perspectives on the synthesis and commercialization of large-area PSCs are discussed last. Most of the growth in commercial PSC applications is likely to be in building integrated photovoltaics and electric vehicle battery charging solutions. This review concludes that blade coating, slot-die coating, and ink-jet printing carry the highest potential for the scalable manufacture of large-area PSCs with moderate-to-high PCEs. More research and development are key to improving PSC stability and, in the long-term, closing the chasm in lifespan between PSCs and conventional photovoltaic cells.

PREDICTIVE MODELING OF MIXED HALIDE PEROVSKITE CELL USING HYBRID L27 OA TAGUCHI-BASED GA-MLR-GA APPROACH

Perovskite photovoltaic cell is regarded as an alternative configuration for the conventional photovoltaic cells predominantly due to its high efficiency. In this paper, a predictive modeling using a hybrid L27 orthogonal array (OA) Taguchi-based Grey relational analysis (GRA), multiple linear regression (MLR) and genetic algorithm (GA) was proposed to optimize the device parameters for better overall performance. The Perovskite photovoltaic cell model is initially constructed and simulated using solar cell capacitance simulator (SCAPS). The final results reveal that the proposed hybrid L27 OA Taguchi-based GRA-MLR-GA approach has effectively optimized the device parameters in which SnO2:F thickness, SnO2:F donor density, ZnO thickness, ZnO donor density, CH3NH3PbI3-xClx thickness, CH3NH3PbI3-xClx donor density, Spiro-OMeTAD thickness and Spiro-OMeTAD acceptor density are predictively tuned at 0.198 μm, 8.973 x 1018 cm-3, 0.039 μm, 8.827 x 1017 cm-3, 0.386 μm, 1.929 x 1013 cm-3, 0.233 μm and 8.984 x 1018 cm-3 respectively. After the predictive modeling, both FF and PCE of the perovskite photovoltaic cell have been improved for ~5.93% and ~5.78% respectively.

Suppression of lowering in conversion efficiency under temperature variation for multijunction laser power converters

Conventional multijunction photovoltaic cells used for optical wireless power transmission, often referred to as laser power converters, currently involve a serious problem. The conversion efficiency lowers under temperature variation more notably than that of single-junction cells, because of changing absorption coefficient and resultant current mismatching among the subcells. Light-trapping using an anti-reflection coating on the front face and a diffuse reflector on the rear face solves this problem, because intensity distribution of the incident light inside the cell remains almost uniform even though the absorption coefficient changes. An angular-selective filter on the front face further improves the efficiency.

Numerical simulation of photovoltaic thermal air panel with phase change materials

Photovoltaic panels make it possible to transform solar radiation into electrical energy and this through photovoltaic cells. The disadvantage of a conventional photovoltaic cell is that its performance decreases as the temperature increases. Indeed, part of the solar radiation is not converted into electricity and dissipates in the form of heat, which increases the temperature of the cell relative to the ambient temperature. Hence, the discovery of new Hybrid PV-Th panel that allows to cool the photovoltaic cells, reduce also the heat exchange transfer and then to increase their yields. This article presents a theoretical and numerical study of a new hybrid Photovoltaic-Thermal solar system equipped with phase change materials (PCM). For this, a digital PV-Th system has been developed in MATLAB environment. Simulations were performed using the optimized model to assess the productivity of the PCM integrated in the PV-Th air panel. The results of the simulations are satisfactory and can be extrapolated for other types of panels where PCMs can be installed. In this work, a prototype air-PCM exchanger based on the use of spherical nodules (PCM), was instrumented and tested on the PV-Th air panel dimensioned specifically for this purpose.

Introducing a 1D numerical model for the simulation of PN junctions of varying spectral material properties and operating conditions

During the last years, innovative concepts of solid-state devices, such as multi-junction solar cells and thermophotovoltaic converters, have emerged as efficient means of direct electricity production. The accurate estimation of the conversion efficiency of such devices using simple yet effective numerical tools is a necessity to optimize their performance. This work presents an in-house code, which is based on the Drift Diffusion Model to simulate p-n junction diodes, under equilibrium (bias voltage application) and non-equilibrium (bias voltage and device illumination) conditions. Under non-equilibrium, illumination can originate from either solar radiation (conventional photovoltaic cell) or a thermally heated emitter (thermophotovoltaic operation). The drift-diffusion and Poisson’s equations are solved using a one-dimensional (1D) finite element Petrov-Galerkin method based on piecewise nonlinear interpolants of second-order accuracy, while the total current is evaluated in a post-process manner using the Scharfetter-Gummel scheme. Initially, the model is verified against the freeware SimWindows. Later on, a parametric analysis on the photovoltaic cell design and operating conditions reveals that its efficiency is highly affected by its total length, the n-type sub-region width, the doping levels of both p and n regions, the semiconductor material type, and, the device’s operating temperature. In contrast to other solvers, this one takes into account the model parameters’ dependence on temperature and electromagnetic spectrum, while it can be extended to incorporate the thermally stimulated electron emission in thermionic-based devices and 2D spatial effects. Finally, the calculated conversion efficiencies can be used to build a Reduced Order Model that can be further coupled with a computational fluid dynamics model to evaluate the overall thermo-electric performance of a solid-state device.

Characterization of a copper susceptor sensitive to solar IR and UV radiation

Renewable energies use has become the best alternative to reduce the damage effects due to global warming. In this work it is presented the characterization for a copper susceptor being sensible to IR and UV sun radiation, the susceptor was installed in the focus of a parabolic antenna reaching temperatures around 300°C. The susceptor is elaborated from type “K” thermocouples as transducers from heat energy to electric energy, thermocouples were mounted on a copper bar which received a chemical treatment in order to obtain an oxide film sensible to IR and UV sun radiation it is shown the absorption specters of the film taking as a reference the air absorption spectres measured with a BRUKER® equipment. Thermocouple array consist of 800 elements connected on parallel and series, final setup will be disposed in a configuration able to reduce atmospheric perturbations and absorb the high sun radiation values available at UPTlax Campus, it has been evaluated the effectiveness of the presented technology as a viable proposal that could be an alternative to the conventional silice photovoltaic cells.

Modern third generation solar photovoltaic technology: Dye sensitized solar cell

Depleting conventional energy resources are forcing the world to search for new and renewable energy resources. Solar energy is one of the potent and abundant energy resource .To use the solar energy to its fullest along with conventional technology has specific limitations. These limitations can be eliminated by use of Dye Sensitized Solar Cell (DSSC). DSSC can be seen as promising future technology. It is advantageous over Silicon (Si) based Photovoltaic (PV) cell in terms cost, easy manufacturing, stability at higher temperature, aesthetics, etc. Also it works in indoor conditions i.e. diffused sunlight which nearly not feasible with conventional PV cells. Now Research and Development Departments of many countries like Japan, Germany, USA, Switzerland, India, China and many firms like G-Cell, Oxford PV, Sony, TATA-Dyesol are working on DSSC to improve its various aspects so as to make it more applicable in various conditions. The paper will discuss the concept, construction, working of DSSC. Also it will illustrate current applications of DSSC.

Integrating Transparent and Conventional Solar Cells TSC/SC

Conventional photovoltaic cells are able to convert the visible light spectrum of solar radiation into electricity; the unused wavelengths of the solar radiation spectrum are dissipated as heat in the system. On the other hand, certain types of transparent solar cells are able to utilize the rest of the solar radiation spectrum. The integration of transparent solar cells with conventional photovoltaic cells enables the system to absorb and utilize both wavelengths of the solar radiation spectrum. In this paper, two models for integrating transparent solar cells with conventional photovoltaic cells are proposed, simulated, and analyzed theoretically. ANSYS software was used to obtain the results for the proposed models. It is an initial theoretical study that shows some first results; it is almost a work in progress. The results showed that the highest efficiency was for the model that had two cooling spaces. The efficiency was increased as the ambient air temperature decreased and the mass flow rate increased. The percentage drop in photovoltaic (PV) cell efficiency decreased as the mass flow rate increased and the ambient temperature decreased, and it had the lowest value when air/water was used for cooling. The efficiency of the transparent solar cell (TSC) increased as the transparency decreased; in order to have higher efficiency, PV efficiency should be high, with low transparency. When added, the transparent solar cell was supposed to increase the harvested energy due to the utilization of the unconverted solar radiation, but it left two negative side effects. The first negative side effect was the reduction of the transmitted radiation to the conventional solar cell due to the transmissivity of the transparent cell. The second negative impact was the increase in the conventional cell temperature due to the additional thermal resistance, which reduced the effectiveness of cooling the cell from above. The proposed models were verified by comparing the results of the standalone PV that were available in the literature with the two models that are proposed in this paper.

On the physical and photo-electrical properties of organic photovoltaic cells based on 1,10-Phenanthroline and 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphine non-fullerene thin films

The active layer of the bulk heterojunction organic photovoltaic cells is typically based on a polymeric blend containing a donor polymer and a fullerene-based polymer electron acceptor. However, in the last decade non-fullerene polymer-based solar cells have seen a rapid progress, due to their extraordinary chemical, thermal and photo stability, and because of their ability to decrease the voltage loss. The conventional Organic Photovoltaic Cells (OPVs), structures based on either P3HT:PCBM bulk heterojunction (BHJ) polymeric blend or P3HT/PCBM bilayer heterojunction, have limited efficiency and stability, in principal due to the fullerene derivatives used as acceptor component. PCBM for example, as many other fullerene derivatives, exhibits some deficiencies, such as: limited chemical and energetic tunability, small range of absorption spectra, morphological instability and relatively high production costs. That is why in the last years, novel non-fullerene materials started to be used in order to overcome the above limits associated with the fullerene acceptors. In this paper two different non-fullerene acceptor materials have been tested as potential candidates for the efficient OPVs based on P3HT donor polymer as main absorber: a new conjugated polymer containing chelating ligands like 1,10-Phenanthroline (Phen), and a small-molecule acceptor like 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphine (TPyP). For both cell configurations a decrease of the voltage loss was obtained, and it was also observed that the thickness of the P3HT donor layer has an important contribution to the output power (Pmax) and fill factor (FF) of the OPV structures (FF and Pmax increased almost two times by decreasing the thickness of the P3HT donor layer).

High-performance semitransparent polymer solar cells floating on water: Rational analysis of power generation, water evaporation and algal growth

Abstract Compared to conventional ground-mounted photovoltaic (PV) cells, floating photovoltaic (FPV) cells open new opportunities for scaling-up solar power generation, especially in highly populated countries that may have competing uses for the available land. Large-scale FPV projects normally deploy old-fashioned crystalline silicon panels that are brittle and difficult to integrate. Polymer solar cells (PSCs) are regarded as a newer and more versatile concept that make quite a splash today. High absorption coefficients, thin active layers and tunable absorption spectra through a synergy of molecular and device engineering promote extensive research on the integration of semitransparent polymer solar cells (ST-PSCs) with smart architecture to deliver both practical and aesthetic benefits. In this work, we propose a new concept of extending ST-PSCs to the field of FPV cells and explore the potential of regulating aquatic environments and organisms. Three groups of high-performance ST-PSCs are fabricated. Maximum efficiency of 13% and average visible transmittance over 20% deliver an optimum trade-off between power generation and transparency among the best-performing ST-PSCs. We develop new experimental approaches and propose a feasibility study on the water evaporation and algal growth by placing the large-area ST-PSCs on bodies of water. To the best of our knowledge, we demonstrate for the first time that the specific transmittance windows with controlled light intensities generated by the ST-PSCs are capable of regulating water evaporation and algal growth, which provides insight into responsible scale-up of FPVs instead of simply blocking the sunlight. The new functions of ST-PSCs pave an intriguing prospect of developing ST-PSCs for practical FPV applications in the near future.

Improving Efficiency of Photovoltaic Cell Using Nanomaterials

Conventional solar cells are not economical and are recently too expensive to the manufacturers for extensive-scale electricity generation. Cost and efficiency is most vital factor in the accomplishment of any solar technology. In order to improve the conversion efficiency, the major research in thirdgeneration photovoltaic (PV) cells is directed toward retaining more sunlight using nanotechnology. Advancement in nanotechnology solar cell via quantum dots (QDs) could reduce the cost of PV cell and additionally enhance cell conversion efficiency. Silicon quantum dots (Si-QDs) are semiconductor nano crystals of nanometers dimension whose electron-holes are confined in all three spatial dimensions. Quantum dots have discrete electronic states. Quantum dots have capacity to change band gap with the adjustment in size of quantum dot. As the quantum dots size fluctuates over a wide range that demonstrates the variety of band gap so it will assimilate or discharge light. In this paper, the generic mathematical models of PV cell are adopted and then I-V and P-V characteristic curves are obtained from selected parameters using MATLAB software. The essential parameters are taken from datasheets. I-V and P-V characteristics curves are obtained for selected model. Silicon quantum dots have the tunable band gap that is added to conventional PV cell and obtain the I-V and P-V curves. After simulation, efficiency and power of Conventional PV cell to quantum dots based PV cell is compared. The property of quantum dots is used in extending the band gap of solar cells and increasing the maximum proportion of incident sunlight absorbed, hence improving efficiency.

A Database for Urdu Text Detection and Recognition in Natural Scene Images

Conventional solar cells are not economical and are recently too expensive to the manufacturers for extensive-scale electricity generation. Cost and efficiency is most vital factor in the accomplishment of any solar technology. In order to improve the conversion efficiency, the major research in third generation photovoltaic (PV) cells is directed toward retaining more sunlight using nanotechnology. Advancement in nanotechnology solar cell via quantum dots (QDs) could reduce the cost of PV cell and additionally enhance cell conversion efficiency. Silicon quantum dots (Si-QDs) are semiconductor nano crystals of nanometers dimension whose electron-holes are confined in all three spatial dimensions. Quantum dots have discrete electronic states. Quantum dots have capacity to change band gap with the adjustment in size of quantum dot. As the quantum dots size fluctuates over a wide range that demonstrates the variety of band gap so it will assimilate or discharge light. In this paper, the generic mathematical models of PV cell are adopted and then I-V and P-V characteristic curves are obtained from selected parameters using MATLAB software. The essential parameters are taken from datasheets. I-V and P-V characteristics curves are obtained for selected model. Silicon quantum dots have the tunable band gap that is added to conventional PV cell and obtain the I-V and P-V curves. After simulation, efficiency and power of Conventional PV cell to quantum dots based PV cell is compared. The property of quantum dots is used in extending the band gap of solar cells and increasing the maximum proportion of incident sunlight absorbed, hence improving efficiency.