I think the most fundamental answer is that the efficiency reduces when the temperature of the solar cell increases. The solar cell acts as a heat engine between the sun and the solar cell. There will be no energy conversion if the temperature of the solar cell reaches that of the sun. There is also a `temperature coefficient' for the open circuit voltage. It can be analytically calculated, and depends on the bandgap of the solar cell. The smaller the bandgap of the solar cell, the more rapidly its performance degrades with increasing temperature.

Good answer

For all solar PV technologies, there is operating temperature range mainly suggested by the manufacturers which is based on STC conditions. However if not given by the manufacturers, there are equations that can be use to calculate it based on the parameters given by the manufacturers. 

In general, the answer to your question is, for all PV systems the higher the increase in operational temperature the lower the efficiency of the module. 

What is read is there will be 2.2mv decrease in pv cell output for each degree rise of temperature.

Hello Smita, the performance of the solar cell decreases with increasing temperature, because this increases the  internal carrier recombination rates, caused by increased carrier concentrations. You can check the reference below for more information:

http://www.sciencedirect.com/science/article/pii/S1876610213000829

I hope this will help you,

Regards

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The temperature coefficient Gamma is 1/Pmax * dPmax/dT. It depends on cell technology and may be as small as -0.25%/K for some thin films, about -0.35%/K for advanced c-Si and -0.45%/K for standard c-Si. The value will be given on all datasheets as standard and is used in simulation programs like PVSYST.

If the output voltage reduces with increase of temperature the efficiency will reduce.

For temperature effects relevant for solar cells with a photocurrent based on diffusing minority carriers, have a look at http://www.pveducation.org/pvcdrom/effect-of-temperature

In fact diffusion constant (both for electron and hole) and intrinsic carrier concentration will be increased when the temperature will increase and reverse saturation current density is increased when these two parameter increased.

With the increase of temperature, the reverse saturation current density is also increased which reduces open circuit voltage that leads to reduce the efficiency.

Please visit: https://www.researchgate.net/publication/319007468_GE05_Study_on_the_Efficiency_of_the_GaInP_2_GaAsGe_Multijunction_Solar_Cell?_sg=WXKjoSmrtIP0SFKDhoU6XMrkiRfzfeFr0m-rSnKFK0s9MN9unEO-Bp5povAc9rShCyHdG83K4jPnyx9i4vVDYTzZ-cZ9v1O9vDivhgdX.t6R7LbMFXEzexOAadBWgxMXM4z32ILefgxao4SzQmKZxvZhsOtlI59r-kcmjZHkld-fgnUqqrXEor6c9UbMWhA

I came late to this questions. As it is a basic question for solar cells i will try to give an answer to it.

Adding to the colleagues above, explicitly expressed the solar cell efficiency decreases with the increase in temperature. It is so that the cell photo current increases slightly with temperature because the increase of the diffusion coefficient of photogenerated electron hole pairs and because the decrease of the babdgap with temperature. On the other side the open circuit voltage decreases with temperature because of the appreciable increase of the reverse saturation current with temperature. The fill factor may slightly decrease with temperature because the increase of the sreies resistance with temperature. The decrease in the opencircuit voltage overweight the increase in the short circuit current such that the solar cell conversion efficiency decreases with the temperature.

Bets wishes