Fig. 4 shows that the current I generated by the solar cell is given as follow:
equation(2)
I=IL−ID−ISH
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where IL is the generated photocurrent, ID is the diode current and ISH is the current through the shunt resistance RSH.
The output voltage V delivered by the solar cell is given as follow:
equation(3)
V=Vj−I⋅RS
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where Vj is the voltage across both diode and shunt resistance and RS is the serial resistance.
The current ID is given by the Shockley diode equation:
equation(4)
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Where I0 is the reverse saturation current, n is the diode ideality factor, q is the elementary charge, k is the Boltzmann's constant, T is the absolute temperature and k T/q is equal to 0.0259 V at a temperature of 25 °C.
The current through the shunt resistance RSH is given as follow:
equation(5)
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Using the Eqs. (3), (4) and (5), the relation (2) becomes:
equation(6)
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The above explicit model has been found more adequate in previous work [21] to characterize the solar cells.
In this present work, we have measured the values of RS and RSH before and after cooling the solar cell. We have obtained some interesting results highlighting the effect of temperature on RS and RSH.