Thus, three steps are involved in generating electricity from light: (i) absorption of photons, resulting in generation of electron–hole pairs, (ii) separation of carriers by the internal electric field created by p–n junction and collection at the electrodes resulting in potential difference and current in the external circuit, and (iii) potential difference at the electrodes of a p–n junction resulting in injection and recombination of carrier׳s which are the causes of losses [4] and [5].