4.3. Resistance losses
Series resistance is due to the bulk resistance of semiconductor, bulk resistance of metal electrodes and due to the contact resistance between semiconductor and metal. Series resistance can be controlled by careful design of the top contact and emitter resistance [27]. Series resistance should be low for better efficiency of the solar cell because higher value of series resistance reduces the short circuit current. The shunt resistance is due to the leakage across the p–n junction, impurities and crystal defects. The value of shunt resistance should be low. This low value of shunt resistance causes reduction in open circuit voltage. Both series and shunt resistance losses decrease the efficiency and fill factor of the solar cell.