Current in a solar cell when temperature increases?

[says]

What happens to current in a solar cell when temperature increases? I found two sources with different information.

1) As solar panel temperature increases, its output current increases exponentially while the voltage output is reduced linearly.'

2) Whereas, this second website says short circuit current increases slightly.

Should I be thinking of short circuit current and output current as two different things?

1) http://www.solar-facts-and-advice.com/solar-panel-temperature.html
2) http://www.pveducation.org/pvcdrom/solar-cell-operation/effect-of-temperature

 

[mfb]

Short circuit current and regular output current (at non-zero voltage) are indeed different things.

I'm not sure if the author of (1) really means "exponentially". Or with a very low coefficient in the exponent, but then you could call it linear...

 

[Baluncore]

As a first guess I would consider...
1. The PN junction voltage falls slightly as temperature rises. Coefficient is about –2.5mV per degree centigrade, per cell.
2. If the PN junction voltage is lower then light with a slightly longer wavelength may be accepted.
3. Most importantly, the resistance of the conductive material in the panel rises in proportion to temperature.
1 & 3 lower the available output voltage with temperature increase and so moves the maximum power point.