Concentrating System’s Design and Performance Analysis for Spacial Solar Array

The effect of radiation intensity and temperature on the performance parameters of a solar panel is investigated experimentally using an indoor experimental setup, designed and constructed locally at Higher Institute for Applied Sciences and Technology, Damascus. The experiments have been carried out under various intensity levels of radiation in the range of 700- 2000W/m2. The experimental results indicate that, radiation intensity has a dominant effect on current parameters. It is found that photocurrent; short circuit current and maximum current have been increased linearly with increasing radiation intensity. So, concentrating system may be regarded as a best choice to enhance the power output of solar system. The power density of the solar panel at 30oC increased from 1.86 mW/cm2 at 1300W/m2 to 3.59 mW/cm2 at 2000W/m2. The role of temperature on the electric parameters of solar panel is also considered. The practical local possible solar panel’s temperature was considered to be in the range of 10–70oC. The experiments cover this temperature range. Experimental results show that all electrical parameters of solar panel such as maximum output power, open circuit voltage, short circuit current, efficiency and fill factor have changed with temperature variation. As well as the amount of changes in these parameters in terms of temperature value have been obtained. According to results, the most significant is the temperature dependence of the voltage which decreases with increasing temperature while the current of the solar panel slightly increases by temperature. On the other hand, it has been observed that solar panel’s temperature has a dramatic effect on voltage parameters. Open circuit voltage and maximum voltage are decrease with increasing solar panel’s temperature. So, the maximum power density of the mono-crystalline and poly-crystalline silicon solar module decreased from 43.4 and 48.76/cm2 to 36.32 and 41.88mW/cm2 for temperature 10oC and 70oC respectively. When testing the effect of temperature on French Photo watt solar cells, obtained 20 years ago and encapsulated in a solar panel locally, in the temperature range of 10–90oC, it was found that, the open circuit voltage decreases by 1.87mV/ oC which is equivalent to 0.3% of the nominal value. The short circuit current intensity decreases by 20mA/oC which is equivalent to 1% of the nominal value. When comparing these values with those of the company presented at its electronic cite, Isc = +0,06%/°C; Voc = -0,34%/°C, one can conclude that aging effect is important on short circuit current intensity.

Influence of concentration of anthocyanins on electron transport in dye sensitized solar cells

In this paper, a theoretical investigation to the effect of the series resistance ( ) on the solar cell output parameters, such as efficiency (η), open-circuit voltage ( ) , output maximum power ( ) , fill factor (FF) and short circuit current( ) was performed. Multisim software was used to achieve the investigation. It is reproduced by using the current-voltage (I-V) characteristics in accordance with double-diode modeling of the solar cell. The results showed that there is a change in the characteristic curve form due to the variation of series resistance values between (0.01- 0.5) Ohm. Moreover, it was found that the fill factor, short circuit current, and open circuit voltage decreased linearly when the value of the series resistance increased. Consequently, the conversion efficiency of the solar cell declined. In other words, the series resistance has a significant effect on the performance of the solar cell.

Growth of Sn(O,S)2 buffer layers and its application to Cu(In,Ga)Se2 solar cells

Gives a detailed theoretical analysis of the response to monochromatic and to composite light (solar AM0 spectrum) at high intensities, when the usual Shockley theory is not valid because the concentration of excess photogenerated carriers may be comparable or exceed the thermal equilibrium value of the carrier concentration. The open-circuit voltage, short-circuit current, I-V curves, maximum power output, fill factor and efficiency of a 1 Omega cm solar cell have been calculated as a function of incident light intensity by solving numerically the nonlinear ambipolar equation and using the general boundary condition at the junction which is formally valid at all illumination intensities. The effect of the series resistance of the solar cell has been estimated by using the lump model and is discussed separately. Where possible, the theoretical results are compared with the experimental results.

Tuning the hole transport layer in the Ca3SbI3 absorber-based solar cells to improve the power conversion efficiency

A novel CMTS-absorber-based heterojunction Solar Cell (SC) with device structure FTO/ZnO/Buffer layer (BL) /CMTS/Se has been numerically modeled and simulated using SCAPS-1D software. Our aim is to identify the most promising sulphur-based buffer layer that offers high efficiency and lower toxicity, which is essential for reducing the carbon footprint. The primary objective is to enhance the efficiency of the SC by optimizing key photovoltaic (PV) parameters of the corresponding buffer layer (BL), absorber layer (AL), along with interface defect density. From the simulations and the energy band diagram, we found that CMTS-based SC with ZrS $$_{2}$$ buffer layer revealed an impressive power conversion efficiency (PCE). The effects of the front electrode’s work function and operating temperature on the device were also investigated. The findings indicate that the device exhibits greater stability and achieves optimum performance at a temperature of 300 K, with an optimized work function value of 5.9 eV (Se). Furthermore, the effects of Series resistance and Shunt resistance were considered in this study. To gain insight into the built-in potential, the capacitance–voltage (C–V) characteristics were also analysed. Device performance was properly explained by analyzing the electric field, generation rate, and both radiative and nonradiative recombination rates. The simulations achieved SC performances with a PCE of 26.01 %, a fill factor (FF) of 83.21 %, a short-circuit current ( $$J_{sc}$$ ) of 27.93 mA/cm 2 , and an open-circuit voltage ( $$V_{oc}$$ ) of 1.11 V.

Ecole Polytechnique Federale de Lausanne, 1015 Lausanne – Switzerland ABSTRACT: The technology transfer of highly efficient solar cell concepts (i.e. passivated emitter and rear cell PERC) to industry can help reduce their production cost. This work appraises three different industrial approaches for the technology transfer and a conventional processing with a fair comparison. A significant improvement compared to conventional processing was obtained. All advanced approaches lead to an increase in open circuit voltage and short circuit current. This testifies to the benefits of improved passivation of the rear surface and a bettered light trapping. The optimal processing window for the advanced approaches has lower fill factor than the conventional processing. However, the reduction does not result in lower conversion potential. Finally, the PERC type devices deliver a significant increase of more than 0.4 % absolute in conversion efficiency. The structure which proved best was based on laser fired contacts (LFC). A maximum efficiency of 17.0 % has been achieved on 1.8 Ωcm multi-crystalline silicon. Keywords: PERC, inkjet, laser ablation, multi-crystalline silicon. 1. INTRODUCTION In recent published studies [1], a roadmap towards lower production cost was delineated. It features higher production volumes, higher efficiency silicon solar cells with respect to conventional present technology and lower silicon wafer thickness. This work addresses the two latter challenges by proposing optimized process sequences. Furthermore, these sequences are applied to multi-crystalline silicon (mc-Si), which has a lower intrinsic production cost. The increased ratio of surface to volume draws the attention to surface passivation. The work will detail different options to locally contact the base through the passivation on the back surface. The adaption of conventional screen printing techniques highlights the value of the here investigated technology transfers for the industry. Different local contacting techniques were already presented in [2-4]. However, differences, especially in back surface passivation and starting material, hindered their direct comparison. This work aims to test each advantageous for the light trapping [7] and for an enhanced passivation potential [8].

Impact of temperature on performance of series and parallel connected mono-crystalline silicon solar cells

This paper presents an 3D TCAD model of crystalline Silicon (c-Si) solar cells. Physical parameters used in the model are discussed. Simulation results are compared to experimental current-voltage curves and solar cell figures of merit namely open-circuit voltage, short-circuit current density, fill factor, and conversion efficiency, allowing us to determine an optimum design for these devices. Particularly, the model is applied to conventional p-type c-Si solar cells with rear contacts based on Laser-Firing technique and to Doped by Laser (DopLa) crystalline Silicon solar cells.

As fossil fuels, the major source of energy used today, create the greenhouse gas carbon dioxide which causes globalwarming, alternative energy sources are necessary in the future. There is a need for different types of renewable energysources. Photovoltaics use the energy of the sun and convert it into electricity. Photovoltaics PV, called also solar cells aremade from light-absorbing materials. When the cell is joined with a load, optically generated carriers create an electriccurrent. The conventional material used for solar cells is the silicon.Another type of solar cells is dye-sensitized solar cells, which is a field of applied research that has been growing rapidly inthe last decade leading to power-conversion efficiency of 10 percent. One major reason for this field is a potentially low-costproduction of solar modules on flexible (polymer) substrate.The aim of this research is to compare the performance of dye-sensitized solar cells to silicon based solar cells in order toreduce the cost of solar cell and increase the efficiency by analysis of their characterization. This work is based onexperimental work for solar cells comprising.The current-voltage characteristics (I–V) of a solar cell reflect the electrical processes in the device. Therefore, the (I–V)curve is selected as means of comparison between experimental data. These (I–V) characteristics were measured for differentlight wavelengths. The parameters of each solar cell, the short circuit current, open-circuit voltage, fill factor and efficiencywere determined in the wavelength range 460 nm to 589 nm.The experimental results show that the cell efficiency for poly-crystalline silicon and dye-sensitized solar cells are nearlyconstant while it increases towards longer wavelengths for mono-crystalline and thin film silicon solar cells.

One of the parameters that limit the efficiency of a thin film solar cell, especially the a-Si and the nc-Si solar cell is the cell thickness. Although thicker film can absorb most of the sun light, the optical generated carriers will recombination through the numerous gap states in the film that obtained lower short circuit current and fill factor. In the controversy, thinner film could not absorb enough sun light that also limit the short circuit current. In this works, we utilize nanowire structure to solve the conflict between the light absorption and the carrier transport. The designed structure has ZnO:Al nanowire array on the substrate. The p-i-n a-Si solar cell structure is grown along the surface of each ZnO: Al nanowire sequentially. Under sunlight illumination, the light is absorbed in the axis direction of the nanowire. However, the carrier transport is along the radial direction of the solar cell. Therefore, the long nanowire could absorb most of the solar light. In the mean time, the thickness of the solar cell still is thin enough for photo-generated carrier transport. The dependence of short circuit current, open circuit voltage and fill factor to the length, diameter and density of ZnO:Al nanowires were simulated.

Organometal trihalide perovskites have been demonstrated as excellent light absorbers for high-efficiency photovoltaic applications. Previous approaches to increasing the solar cell efficiency have focused on optimization of the grain morphology of perovskite thin films. Here, we show that the structural order of the electron transport layers also has a significant impact on solar cell performance. We demonstrate that the power conversion efficiency of CH3NH3PbI3 planar heterojunction photovoltaic cells increases from 17.1 to 19.4% when the energy disorder in the fullerene electron transport layer is reduced by a simple solvent annealing process. The increase in efficiency is the result of the enhancement in open-circuit voltage from 1.04 to 1.13 V without sacrificing the short-circuit current and fill factor. These results shed light on the origin of open-circuit voltage in perovskite solar cells, and provide a path to further increase their efficiency. Ongoing efforts are devoted to raising the efficiency of solar cells in converting energy from solar radiation. Now, improved structural order in the charge transport layers of perovskite solar cells is shown to increase the efficiency from 17.1% to 19.4%.

Ribbon growth on substrate (RGS) is a novel technique to produce thin sheets of silicon for solar cells with high throughput directly from the melt without a slicing step. By this kind of process the amount of impurities incorporated and the temperature gradients during the solidification are remarkable higher then e.g. in a block casting process. Solar cells produced on RGS material can reach sufficient efficiencies above 12 %, but show unusual properties. The short circuit current may reach exceptionally high values beyond 30 mA/cm2, which are usually only observed in monocrystalline silicon solar cells. The fill factor and the open circuit voltage, however, are lower than expected. The dark current-voltage (I-V) characteristic of such solar cells shows ideality factors (giving the steepness of the forward IV-characteristic) well above two, in disagreement with the theory for a simple emitter-base diode. These unusual properties are caused by the existence of a 3-dimensional network of inversion channels formed by densely packed precipitates around dislocations. These channels are able to collect minority carriers in the bulk of the solar cells and lead them to the pn junction. Thus, in spite of the low diffusion length, the collecting volume is drastically enhanced. It is possible to visualize and investigate the inversion channels by EBIC (electron beam induced current) measurements using special sample geometries. Under forward bias these channels may act as preferred injection sites. A physical model for the inversion channels is proposed explaining for the first time ideality factors above two over a large bias range.

All p-i-n hydrogenated amorphous silicon oxide thin film solar cells for semi-transparent solar cells