Current Issue : January-March Volume : 2022 Issue Number : 1 Articles : 5 Articles
The traditional perturbation and observation (P&O) maximum power point tracking (MPPT) algorithm of a structure is simple and low-cost. However, the P&O algorithm is prone to divergence under solar radiation when the latter varies rapidly and the P&O algorithm cannot track the maximum power point (MPP) under partial shading conditions (PSCs). This study proposes an algorithm from the P&O algorithm combined with the solar radiation value detection scheme, where the solar radiation value detection is based on the solar photovoltaic (SPV) module equivalent conductance threshold control (CTC). While the proposed algorithm can immediately judge solar radiation, it also has suitable control strategies to achieve the high efficiency of MPPT especially for the rapid change in solar radiation and PSCs. In the actual test of the proposed algorithm and the P&O algorithm, the MPPT efficiency of the proposed algorithm could reach 99% under solar radiation, which varies rapidly, and under PSCs. However, in the P&O algorithm, the MPPT efficiency was 96% under solar radiation, which varies rapidly, while the MPPT efficiency was only 80% under PSCs. Furthermore, in verifying the experimental results, the proposed algorithm’s performance was higher than the P&O algorithm....
Numerical modelling is used to confirm experimental and theoretical work. The aim of this work is to present how to simulate ultrathin hydrogenated amorphous silicon- (a-Si:H-) based solar cells with a ITO BRL in their architectures. The results obtained in this study come from SCAPS-1D software. In the first step, the comparison between the J-V characteristics of simulation and experiment of the ultrathin a-Si:H-based solar cell is in agreement. Secondly, to explore the impact of certain properties of the solar cell, investigations focus on the study of the influence of the intrinsic layer and the buffer layer/absorber interface on the electrical parameters (JSC, VOC, FF, and η). The increase of the intrinsic layer thickness improves performance, while the bulk defect density of the intrinsic layer and the surface defect density of the buffer layer/i-(a-Si:H) interface, respectively, in the ranges [109 cm-3, 1015 cm-3] and [1010 cm-2, 5 × 1013 cm-2], do not affect the performance of the ultrathin a-Si:H-based solar cell. Analysis also shows that with approximately 1 μm thickness of the intrinsic layer, the optimum conversion efficiency is 12.71% (JSC = 18:95mA · cm−2, VOC = 0:973V, and FF = 68:95%). This work presents a contribution to improving the performance of a-Si-based solar cells....
In this paper, optical losses in CdS/CdTe solar cells are calculated on the basis of the designated reflective index of various frontal layers using an OPAL2 calculator for the first time. Two types of glass (0.1 mm ultra-thin Schott and 1.1 mm standard borosilicate glass) were assumed to be coated by different Transparent-Conducting-Oxides (TCOs) such as SnO2:F, ZnO:Al, and ITO forming frontal layers for CdS/CdTe solar cells in superstrate configuration. Absorption, reflectance, transmittance, and consequently optical bandgap energies are calculated as a function of common thicknesses, used in the literature. The results show that an increase in TCO thickness led to a decrease in optical band gap as well as an enhancement in contact potential difference, which can deteriorate device performance. The optimum thickness of 100 nm for SnO2:F was calculated, while 200 nm for ZnO:Al and ITO show reasonable optical losses caused by reflections at the interfaces’ and the layer’s absorption. It is seen that 80 to 150 nm CdS on ITO might be an effective range to satisfy a high short circuit current and low defect densities at the CdS/CdTe interface. Finally, a minimum 2 μm thickness for the CdTe on the ultra-thin Schott glass coated by optimum layers can result in the highest short circuit current of 28.69 mA/cm2. This work offers a practical equivalent strategy to be applied for any superstrate solar cells containing TCO and CdS frontal layers....
Owing to the favorable geographical location, Bangladesh captures a good amount of solar radiation per day. The proper utilization of this solar energy may reduce the country’s energy demand to a great extent. Bangladesh government has already made a master plan to utilize the abundant solar energy in different ways with a capacity development target of 600 MW by the end of 2021. Until 2018 a total capacity of 220 MW of solar power could be achieved by installing 6.9 million solar home systems (SHSs). On the other way, rooftop solar and solar mini-grid projects facilitated the capacity of 3.07 MW and 5 MW, respectively. A capacity of 32 MW could also be touched by solar irrigation projects with more than 1300 pumps for serving country’s rural people, and solar-diesel hybrid solution program (by installing 138 small power stations) has been supporting the telecom operators. Bangladesh power development board (BPDB), and Infrastructure Development Company Limited (IDCOL) have been promoting numerous research-development solar projects to many governments and private universities to build sustainable energy equipped country....
In the present study, we provide useful data related to one of the most promising materials in thin-film solar cell technologies: Cu2ZnSnS4 (CZTS) kesterite structures. Sol-gel spin coating and chemical bath deposition methods were used to fabricate and further investigate Mo/CZTS/CdS/ZnO/AZO heterostructures. In order to examine the crystal structure of the samples, Raman scattering measurements using two excitation wavelengths (514.5 nm and 785 nm) were performed. Three Raman bands related to CZTS were found, as well as one that had its origin in CdS. By using laser ablation and performing Raman spectroscopy on these modified samples, it was shown that during the manufacturing process a MoS2 interlayer was formed between the CZTS and Mo layers. Our method proved that the CZTS layer in a multilayer device structure fabricated by solution-based methods can be decomposed, and thus a detailed analysis of the layer can be performed. Subsequently, current-voltage curves were investigated in terms of the essential electrical properties of glass/Mo/p-CZTS/n-CdS/ZnO/AZO junctions and occurring current transport mechanisms. Finally, AFM data were acquired to study the surface topography of the studied samples. The images showed that these surfaces had a uniform grain structure....
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