Solar Cells最新文献

An investigation has been made into the effect of photoelectrode thickness on the photovoltaic properties of cadmium sulphide/electrolyte solar cells. CdS photoelectrodes of various thicknesses doped with 0.25 wt.% arsenic were prepared by a chemical deposition process on plane mirror smooth stainless steel substrates. An electrode/ electrolyte junction cell was designed for use in a glass cuvette and has been analysed in terms of its electrical parameters. The thickness of the photoelectrode was found to cause significant changes in cell parameters such as short-circuit current, open-circuit voltage, series and shunt resistances, efficiency, fill factor, junction quality factors and flat band potential.

A mathematical approach to the power management problem in photovoltaic power systems is developed. Loads are classified into four general categories and to a number of priorities. The problem is formulated as a one-resource allocation problem and solved using dynamic programming techniques. Illustrative examples demonstrate the applicability of the new approach.

A post-deposition process for optimizing the efficiency of thin film CdTe/CdS solar cells deposited by physical vapor deposition has been developed and the effects of the individual process steps on the materials and device properties have been analyzed. A 400 °C heat treatment with CdCl₂ restructures the CdTe resulting in enhanced grain size and crystallographic reorientation. Structural and optical measurements indicate interdiffusion of sulfur and tellurium during the heat treatment resulting in formation of a CdS_xTe_1−x layer with a narrower band gap than CdTe. Bifacial current-voltage and quantum efficiency analysis of the CdTe devices at various stages of the optimization process shows the evolution of the device from a p-i-n structure to a heterojunction. A chemical treatment improves the open circuit voltage ($\text{V}{}_{\mathrm{oc}}$) and Cu/Au contact to the CdTe. The optimization process can be applied to cells using CdTe and CdS deposited by different methods.

Many gases used in photovoltaic cell manufacture are inherently hazardous to human health. Thus, the risk to occupational and public health presented by these gases must be minimized through the use of engineering, administrative and personal control strategies. In this report a checklist of such controls is presented for the Handling and storage, distribution, use and disposal of toxic gases in photovoltaic cell manufacture. Because of the increasing emphasis being placed on controlling hazards of toxic gases, the checklist will probably expand over time. In this context, the authors welcome suggestions and revisions.

This paper presents a method for determining the optimum junction depth of a passivated emitter solar cell for a given surface dopant concentration. It takes into account the influence of the transparency factor on the recombination current, considering in the optimization two different surface recombination velocities corresponding to passivated and non-passivated zones. The results, obtained for different characteristics of the contact grid, show that the design of the emitter of a solar cell is strongly dependent on the technology used to produce the grid. Finally, the method proposed shows maximum efficiencies around 3×10¹⁹ cm⁻³, practically independent of the surface doping concentration depth over a large range of values.