Effect the Technique of Light Trapping on the Performance of Simple Junction n-p Solar Cells Based on GaAs and Si

Light trapping enhances the absorption of active materials in photovoltaic cells. The use of light trapping results in a thinner active region in a solar cell, which lowers the production cost by reducing the amount of material used, and increases the energy conversion efficiency by facilitating carrier collection and enhancing the open circuit voltage. There are many light trapping techniques have been introduced in order to enhance absorption of the active layer in the thin film solar cell. Antireflective layers reduce reflection losses at interfaces, Light Trap: force the light to stay longer in the layer by changing the structure of interfaces. In the present work we proposed a technique based on closed-form analytical calculation to analyse the effect of light trapping on the performance of simple Si and GaAs np junction solar cells. Particular importance is paid to light reflection. A comparison is carried out between three types of cells, with antireflection coating, with texturing on the front of the cell, and with a lambertinne reflector. The conversion efficiency increased from 23.00 % in a cell with GaAs texturing on the front and a rear reflector (incoherent reflection) to 23.90 % and for Si it passes from 15.05 % to 16.00 %. GaAs solar cell exhibits a maximum efficiency around 28.68 % with a Lambertian reflector. An efficiency of 19.37 % is obtained with Si when a Lambertian reflector is inserted

Solar cell degradation under open circuit condition in out-doors-in desert region

AbstractThe reliability of solar cells is an important parameter in the design of photovoltaic systems and particularly for cost estimation. Solar cell degradation is the result of various operating conditions; temperature is one of most important factors. Installed PV modules in desert regions are subjected to various temperature changes with significant gradient leading to accelerated degradation. In the present work, we demonstrate the influence of open-circuit condition on the degradation of PV modules. The experiment is carried out in the desert region of ADRAR (southern Algeria) using two modules IJISEL of single-crystal silicon. A continuous monitoring allows analysis of both performances of modules for duration of 330days. The module in open-circuit condition reaches higher temperature means than the module in charging condition; therefore, it undergoes a higher degradation. By simulation, we found that the life of a PV module (whose power output is close to 50%) in a condition of an open-circuit in the desert region could be reduced to 4years, and that has a significant impact on economy

Metal phthalocyanine gas sensors

SIGLEAvailable from British Library Document Supply Centre- DSC:DX95995 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Quasi-ballistic Transport in Submicron Hg0.8Cd0.2Te Diodes: Hydrodynamic Modeling

International audienc

Effects of temperature and series resistance on GaAs concentrator solar cell

Concentrators use reflection or refraction of light, or a combination of both, but concentration of light leads to a crucial heating of the cell, which involves degradation of its performance. However, solar cells especially conceived for concentration can support very intense illuminations as far as an active cooling is assured. In this work, a GaAs solar cell with AlxGa1-x As window layer, operating under low injection conditions, has been studied with temperature and solar concentration. The temperature corresponding to each concentration was calculated, and then used in the calculation of photovoltaic parameters. The study was carried out under free mode conditions (without heat sink) and then under forced conditions (with a cooling system) in order to demonstrate the importance of cooling in the concentrator solar cells. The effect of series resistance on solar cell characteristics has also been studied. The simulation was carried out using SCAPS-1D simulator. The results were compared with those obtained theoretically; a good agreement was found between the two models

Solar Cell Degradation by Electron Irradiation Effect of Irradiation Fluence

Solar cells used in orbit are exposed to radiation environment mainly protons and high energy electrons. These particles degrade the output parameters of the solar cell. The aim of this work is to characterize the effects of electron irradiation fluence on the J (V) characteristic and output parameters of gaAs solar cell by numerical simulation. The results obtained demonstrate that the electron irradiation-induced degradation of performances of the cells concerns mainly the short circuit current