Voltage Characteristics Of Solar Cells Research Articles

Parameters extraction of solar cells using modified JAYA algorithm

Solar energy has been receiving tremendous interest in this decade, due to their broad applications in areas of renewable energy sources. To identify the accurate modeling of current and voltage characteristics of solar cells will help to improve the performance of solar energy systems. However, the I-V characteristics are multimodal and complex non-linear equations making these optimization techniques to get trapped into local optima, low efficiency due to an initial solution far from the global optimal solution. Therefore, this paper proposes a modified JAYA (MJA) algorithm for estimating the solar cells parameters. In MJA, the modified solution updating phase by hybrid classical JAYA operator with differential evolution (DE/rand/1) operator, and self-adaptive population size are employed to improve global searching ability. In order to validate the feasibility and performance of the proposed MJA algorithm, experimental studies are carried out in identifying the parameters of a single diode, and double diode models and full comparison with different variants of JAYA, DE and other well-established algorithms in the last two years. Experimental results demonstrate that MJA can obtain better performance in terms of robustness and accuracy than all compared algorithms.

S-Shaped Current–Voltage Characteristics in Solar Cells: A Review

S-shaped current–voltage ( I – V ) characteristics are a frequently occurring hurdle in the development of new solar cell material combinations and device architectures. Their presence points to the existence of a charge transport bottleneck that needs to be removed in order to unlock high fill factors and power conversion efficiencies. In this review, examples of studies in which s-shaped I – V curves have appeared are presented, and the cause and mitigation are discussed. Different solar cell material systems are often treated by separate communities, thereby, also the physics of s-shaped I – V curves have been treated separately. This review covers the main solar cell technologies—silicon, thin film, organic, hybrid—with the aim to provide an overarching picture of the common mechanisms and universal guidelines for mitigation of s-shaped I – V characteristics in emerging solar cell technologies. Except for a few studies on organic solar cells, s-shaped I – V curves are reported to result from charge transport barriers at one of the (selective) contact layers that can be overcome by interface engineering and doping.

Solar Cell Manufacturing Method with the Structure of the Bulk Heterojunction Based on Organic Semiconductors with a Direct Architecture

This article presents the results of research output voltage characteristics of solar cells on an organic basis with the use of P3HT: PCBM system. There were produced organic solar cells in a coating in air, current-voltage characteristics were measured. It was determined the characteristic influence of a substrate cleaning and annealing temperature of layers applied on fill factor and conversion efficiency.

Structural, Magnetic Properties and Dye-Sensitized Solar Cells Application of Pure and La Doped BiFeO3 Powders Prepared by Sol-Gel

Multifunctional materials Bi1-xLaxFeO3 (x = 0.05, 0.10, 0.15, 0.20) powders with and without annealing (700°C) were prepared by sol-gel method to improve the magnetic and optical properties. The particle size, chemical structures, and chemical compositions of the powders were investigated by bright-field TEM, XRD, SADP, and XRF. The bright-field TEM results show the particle size of the prepared Bi1-xLaxFeO3 powders without annealing (around 200 nm) is less than that of the annealed Bi1-xLaxFeO3 powders (more than 500 nm). The XRD results of the powders without annealing show the formation of rhombohedral structure of BiFeO3 with Bi24Fe2O39 as impurity phase in all samples, whereas the prepared powders annealed at 700°C have a higher phase purity. The M – H hysteresis loop of the powders with annealing and without annealing were measured by vibrating sample magnetometer at room temperature up to the field of 10 kOe. The results demonstrate that the powders with higher purity phase and larger particle size were larger saturation magnetization. The saturation magnetizations were increased by increasing the La doping content. The optical absorption edge result can be considered energy band gap (∼2.0–2.2 eV) of all prepared powders. The prepared powders were used as photoelectrode in dye-sensitized solar cell applications. The current density versus voltage characteristics of solar cell were measured under illumination of simulated sunlight coming from a solar simulator with the radiant power of 100 mW/cm2 to obtain photocurrent, photovoltage, and overall photoconversion efficiency of solar cells. The power conversion, photocurrent density and photovoltage depending on purity, particle size with and without annealing powders using as photoelectrode in dye sensitized solar cells are discussed.

Role of Oxygen Adsorption in Nanocrystalline ZnO Interfacial Layers for Polymer–Fullerene Bulk Heterojunction Solar Cells

Colloidal zinc oxide (ZnO) nanoparticles are frequently used in the field of organic photovoltaics for the realization of solution-producible, electron-selective interfacial layers. Despite of the widespread use, there is a lack of detailed investigations regarding the impact of structural properties of the particles on the device performance. In this work, ZnO nanoparticles with varying surface-area-to-volume ratio were synthesized and implemented into polymer-fullerene bulk heterojunction solar cells with a gas-permeable top electrode. By comparing the electrical characteristics before and after encapsulation, it was found that the internal surface area of the ZnO layer plays a crucial role under conditions where oxygen can penetrate the solar cells. The adsorption of oxygen species at the nanoparticle surface causes band bending and electron depletion next to the surface. Both effects result in the formation of a barrier for electron injection and extraction at the ZnO/bulk heterojunction interface and were more pronounced in case of small ZnO nanocrystals (high surface-area-to-volume ratio). Different transport-related phenomena in the presence of oxygen are discussed in detail, i.e., Ohmic losses, expressed in terms of series resistance, as well as the occurrence of space-charge-limited currents, related to charge accumulation in the polymer-fullerene blend. Since absorption of UV light can cause desorption of adsorbed oxygen species, the electrical properties depend also on the illumination conditions. With the help of systematic investigations of the current versus voltage characteristics of solar cells under different air exposure and illumination conditions as well as studies of the photoconductivity of pure ZnO nanoparticle layers, we gain detailed insight into the role of the ZnO nanoparticle surface for the functionality of the organic solar cells.

Structural Aspects of Band Gap Grading in Cu(In,Ga)(S,Se)2-Based Solar Cells

Structural analysis of multinary Cu(In,Ga)(S,Se)2 films demonstrates the feasibility of compositional grading in the depth of the absorber with respect to the S/(S+Se) ratio. Solar cells prepared from films with moderate S/Se gradients exhibit high open circuit voltages and efficiencies up to 13.9%. In this contribution we investigate strong S/Se gradients. Of particular interest are the thickness of a nearly homogeneous top layer as well as the impact of the crystallinity on the current voltage characteristics of solar cells. We show that the crystallinity of a homogeneous top layer strongly correlates with the performance of the corresponding devices.

A Simple Solar Cell Characteristics Plotter

A simple and economical system for the measurement of current voltage characteristics of solar cells has been described. Facility for the detection and marking of maximum power point on the I-V characteristic of the cell under illumination has also been added to facilitate the solar cell panel designer to avoid the hot spots in the panel.