What effect does increasing temperature have on the voltage and current output of a solar cell and why?

I am doing a physics experiment for a school assignment and i have conducted an experiment the yielded results that indicate that as the temperature of the solar cell increases, the voltage output decrease. However, I also found that as the temperature increases, so does the current output.

I can't figure out why this is happening please help.

You would think hot temperatures equal a lot of sunny weather and this would be great for solar panels.  Sun is a photovoltaic panel’s best friend; however, high temperatures can be their worst enemy.

So what do higher temperatures do to solar photovoltaic panels?  As temperatures rise, the efficiency of solar panels decreases.  Heat causes electrical resistance to the flow of electrons.  On days where the temperature is more than 75 degrees, the electrical resistance makes the voltage fall thereby producing less kilowatts per hour.  Your roof is much hotter than temperatures on the ground.  That’s why solar panels are not mounted flat to a roof.  There’s usually a few inches of spaces between the panels and roof so air flow can easily pass through and cool the panels down.

There are some photovoltaic panels that are designed specifically to operate in hotter temperatures.  These panels have a higher temperature coefficient.  This is especially important in high heat climates like Arizona or New Mexico, but probably wouldn’t make too much of a difference in New England (except maybe this year).  If you do live in one of these areas, you should speak to your solar installer to make sure they are using they right equipment for your region.

Please note:  Solar thermal panels used to heat water can withstand high temperatures without any degradation.  In fact, hotter temperatures would actually be better for these types of modules.