Solar Cell construction

Silicon-based PV semiconductor solar cells have been used to demonstrate the most practical and reliable application of the photovoltaic effect. A simple, rugged semiconductor junction can be produced from single-crystal silicon. Low resistance contacts are added to tap the electrical energy produced when the cell is exposed to sunlight.

Approximately a DC voltage of 0.45 volts is generated across each cell regardless of the dimensions for this particular cell architecture. The DC current and thus the power available are strictly dependent on the cell area exposed to the sun and the absorption capability of the silicon wafer, which is located between the two contacts, as illustrated in Figure. It is important to mention that the higher the absorption capability of the semiconductor material, the higher the PV voltage will be across the cell terminals.

Higher voltage is possible by connecting the cells in series, while higher output power is possible by connecting the cells in parallel. Solar cells can be installed on glass-filled polyester substrate. The net cell output is the product of solar intensity (I = 100 mW/cm2) and the conversion efficiency of the device, which is typically now about 16 percent for a silicon cell. A solar module may contain several cells connected in series and parallel

 

Figure – Solar cell construction