Effect of Temperature on Electrical Parameters of Phosphorous Spin–on Diffusion of Polysilicon Solar Cells

Effects of temperature on electrical parameters of polysilicon solar cells, fabricated using the phosphorous spin-on diffusion technique, have been studied. The current density–voltagecharacteristics of polycrystalline silicon solar cells were measured in dark at different temperaturelevels. For this purpose, a diode equivalent model was used to obtain saturation current densitiesmeasured at the required temperatures. The experimental results showed that the increase intemperature from 27 to 70˚C produced a rapid increase in the saturation current densities from 0.00003to 0.0005A. The changes in the open circuit voltage and the short circuit current density were found tobe linear with the temperature variations: about 3 mV/˚C reduction in the open circuit voltage wasobserved. Measurements of the short circuit current density revealed a very small dependency of thecurrent density on the temperature variations. Accordingly, the short circuit current density increasedfrom 17.8 to 18.4 mA with increase in temperature from 27 to 107˚C. Measurements of the outputpower versus load resistance were obtained at different temperature levels. The results showed that theoutput power dropped by 30% with temperature rise from 27 to 107˚C.