Solar Cell Parameters Extraction from a Current- Voltage Characteristic Using Genetic Algorithm

The determination of solar cell parameters is very important for the evaluation of the cell performance as well as to extract maximum possible output power from the cell. In this paper, we propose a computational based binary-coded genetic algorithm (GA) to extract the parameters (I0, Iph and n) for a single diode model of solar cell from its current-voltage (I-V) characteristic. The algorithm was implemented using LabVIEW as a programming tool and validated by applying it to the I-V curve synthesized from the literature using reported values. The values of parameters obtained by GA are in good agreement with those of the reported values for silicon and plastic solar cells. change to “After the validation of the program, it was used to extract parameters for an experimental I-V characteristic of 4 × 4 cm2 polycrystalline silicon solar cell measured under 900 W/m. The I-V characteristic obtained using GA shows excellent match with the experimental one. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3100

Effects of Annealing on Structural Properties of Copper Zinc Tin Sulphide (CZTS) Material

Copper Zinc Tin Sulphide compound was synthesized from its elemetal precursurs using simple solid state method. Being quarternary material, there is a large probability of formation of secondary phases like SnS, ZnS, CuS during the material growth process and it requires a detail investigation on the effects of synthesis parameters on the composition and structural properties of the CZTS compound. Here we report the study of effects of annealing on the synthesized compound. The annealing was performed at two different temperatures in the presence of Sulphur. The structural and compositional properties of the as-grown and annealed samples were examined by X-ray diffraction (XRD) and Energy Dispersive Analysis of X-Ray (EDAX). The formation of Kesterite CZTS phase was confirmed by Raman Spectroscopy. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3102

Effects of Annealing on Structural Properties of Copper Zinc Tin Sulphide (CZTS) Material

Copper Zinc Tin Sulphide compound was synthesized from its elemetal precursurs using simple solid state method. Being quarternary material, there is a large probability of formation of secondary phases like SnS, ZnS, CuS during the material growth process and it requires a detail investigation on the effects of synthesis parameters on the composition and structural properties of the CZTS compound. Here we report the study of effects of annealing on the synthesized compound. The annealing was performed at two different temperatures in the presence of Sulphur. The structural and compositional properties of the as-grown and annealed samples were examined by X-ray diffraction (XRD) and Energy Dispersive Analysis of X-Ray (EDAX). The formation of Kesterite CZTS phase was confirmed by Raman Spectroscopy. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3102

Determination of Thickness and Optical Parameters of Thin Films from Reflectivity Spectra Using Teaching-Learning Based Optimization Algorithm

In this paper, we report a simple method to extract thickness and refractive index of thin-film from experimentally measured reflectivity spectra using teaching-learning based optimization (TLBO) algorithm. The algorithm finds thickness and refractive index by fitting an experimentally measured reflectivity spectra with theoretically ones generated by transfer matrix approach. The value of refractive index as a function of wavelength is determined by considering sellmeier dispersion relation. The algorithm is implemented by means of an interactive numerical simulation using LabVIEW as a programming tool. To check the effectiveness of the self-developed program, it is tested on different thin-film samples prepared from some commonly used optical materials such as MgF2, Al2O3 and SiO2 using electron beam evaporation technique. The values of thicknesses and refractive index spectra for different thin-film samples obtained by TLBO algorithm are verified using standard spectroscopic ellipsometry measurements. It is found that there is an excellent agreement between the results obtained by the TLBO algorithm and those by ellipsometry. It is also demonstrated that a simple reflectivity measurements give the valuable information about the thickness and dispersive refractive index over a range of wavelengths, which are obtained by our self-developed simulation program based on TLBO algorithm

Suppression of Optical Feedback in Laser Diodes Using Multilayered Broad-band Ultra-low Reflective Facets-coating

The multilayered anti-reflection coating (ARC) has been designed and implemented on the facets of edge-emitting laser diode in order to achieve ultra-low reflectivity over a broad wavelength range for suppression of optical feedback in the laser cavity. The design of the multilayer ARC has been obtained by a self-developed program based on genetic algorithm (GA) to achieve low-reflectivity of the order of 0.1 % over a spectral width of 50 nm around the central lasing wavelength of 818 nm and successfully implemented on the laser-diode facets. The effects of facets coating on the optical power emission and the spectral response of the lasers have been investigated. It is demonstrated that the simple design of multilayered ARC obtained using a self-developed GA can successfully reduce the optical feedback from the cavity and prevent the lasing action from the structure, which can be very useful for the fabrication of superluminescent Light Emitting Diodes (SLEDs)

Numerical simulation of tin based perovskite solar cell: Effects of absorber parameters and hole transport materials

The organometal perovskite solar cells have shown stupendous development and have reached power conversion efficiency (PCE) of 22.1 %. However, the toxicity of lead in perovskite solar cells is a major challenge towards their incorporation into photovoltaic devices and thus needs to be addressed. Tin perovskite (CH3NH3SnI3) have attracted a lot of attention recently and could be a viable alternative material to replace lead perovskite in thin film solar cells. A detail understanding of effects of each component of a solar cell on its output performance is needed to further develop the technology. In this work, we performed a numerical simulation of a planar heterojunction tin based perovskite solar cell using SCAPS (Solar Cell Capacitance Simulator). Results revealed that thickness and defect density of the absorber material strongly influence the PCE of the device. Various types of hole transporting material (HTM) were compared and analysed to improve the performance of the solar cell. Parameters such as hole mobility and acceptor density of HTM also signified dependence on PCE of the device. These results indicate the possibility to design, fabricate and enhance the performance of tin based perovskite solar cells

Numerical simulation of tin based perovskite solar cell: Effects of absorber parameters and hole transport materials

The organometal perovskite solar cells have shown stupendous development and have reached power conversion efficiency (PCE) of 22.1 %. However, the toxicity of lead in perovskite solar cells is a major challenge towards their incorporation into photovoltaic devices and thus needs to be addressed. Tin perovskite (CH3NH3SnI3) have attracted a lot of attention recently and could be a viable alternative material to replace lead perovskite in thin film solar cells. A detail understanding of effects of each component of a solar cell on its output performance is needed to further develop the technology. In this work, we performed a numerical simulation of a planar heterojunction tin based perovskite solar cell using SCAPS (Solar Cell Capacitance Simulator). Results revealed that thickness and defect density of the absorber material strongly influence the PCE of the device. Various types of hole transporting material (HTM) were compared and analysed to improve the performance of the solar cell. Parameters such as hole mobility and acceptor density of HTM also signified dependence on PCE of the device. These results indicate the possibility to design, fabricate and enhance the performance of tin based perovskite solar cells

Numerical Simulation of Tin Based Perovskite Solar Cell: Effects of Absorber Parameters and Hole Transport Materials

The organometal perovskite solar cells have shown stupendous development and have reached a power conversion efficiency (PCE) of 22.1%. However, the toxicity of lead in perovskite solar cells is a major challenge towards their incorporation into photovoltaic devices and thus needs to be addressed. Tin perovskite (CH3NH3SnI3) have attracted a lot of attention recently and could be a viable alternative material to replace lead perovskite in thin film solar cells. A detail understanding of effects of each component of a solar cell on its output performance is needed to further develop the technology. In this work, we performed a numerical simulation of a planar heterojunction tin based perovskite solar cell using SCAPS (Solar Cell Capacitance Simulator). Results revealed that thickness and defect density of the absorber material strongly influence the PCE of the device. Various types of hole transporting material (HTM) were compared and analysed to improve the performance of the solar cell. Parameters such as hole mobility and acceptor density of HTM also signified dependence on PCE of the device. These results indicate the possibility to design, fabricate and enhance the performance of tin based perovskite solar cells

Reduction of Fermi Level Pinning and Recombination at Polycrystalline CdTe Surfaces by Laser Irradiation

Laser processing of polycrystalline CdTe is a promising approach that could potentially increase module manufacturing throughput while reducing capital expenditure costs. For these benefits to be realized, the basic effects of laser irradiation on CdTe must be ascertained. In this study, we utilize surface photovoltage spectroscopy (SPS) to investigate the changes to the electronic properties of the surface of polycrystalline CdTe solar cell stacks induced by continuous-wave laser annealing. The experimental data explained within a model consisting of two space charge regions, one at the CdTe/air interface and one at the CdTe/CdS junction, are used to interpret our SPS results. The frequency dependence and phase spectra of the SPS signal are also discussed. To support the SPS findings, low-temperature spectrally-resolved photoluminescence and time-resolved photoluminescence were also measured. The data show that a modest laser treatment of 250 W/cm2 with a dwell time of 20 s is sufficient to reduce the effects of Fermi level pinning at the surface due to surface defects

Cu2Znsns4 Thin-Films Grown By Dip-Coating: Effects Of Annealing

Recently Cu2ZnSnS4, i.e. Copper Zinc Tin Sulphide (CZTS), has emerged as a potential candidate for low-cost solar photovoltaics (PV) material because of it is relatively non-toxic and ingredient elements are earth abundant. However, achieving phase controlled, stoichiometric film of CZTS using low-cost technique is the key issue in development of CZTS based solar cell. Here, we report a study on structural and optical properties of CZTS films grown by dip-coating in view of its application as an absorber in thin film solar cells. The films were deposited by dipping glass substrates into the solution prepared by dissolving cation metal salts and thiourea in methanol. It is followed by drying the films in air at fixed temperature. The dip coated films were then annealed at 623 K, 723 K and 823 K. The influence of annealing on various structural and optical properties of the films were investigated by means of X-ray diffraction (XRD), Raman scattering spectroscopy, Scanning electron microscopy (SEM) and Diffused reflection spectroscopy. It was observed that the film annealed at 823 K shows good quality Kesterite structure of CZTS with preferred orientation of (112), (220) and (312) planes as revealed by the XRD pattern. The diffuse reflection spectra confirm the direct band-gap of 1.42 eV, which is very close to the optimum value for the semiconductor material as an absorber in solar-cells. Raman scattering with two different excitation wavelengths showed that other binary phases including the parasitic phases such as ZnS were not present. It also confirmed the characteristics signature of dominant CZTS phase in the film