Efficiency enhancement through flat intermediate band in Quantum dot solar cell

Abstract

Quantum dots (QD) are playing a vital role due to their multifunctionality such as small size and tuning the range of band and have achieved a considerable attention in the recent decade. In recent research, the efficiency of the solar cell (SC) has greatly been increased by application of QD. If these dots are grown systematically, may lead to the formation of the intermediate band (IB) which leads to the absorption of photons with energy less than the actual band through intermediate absorption process and hence increasing the carrier generation rate which ultimately results in high current density keeping the output voltage unaffected. In this paper, we have proposed a method to control the band flatness of the IB in InAs/GaAs QDSC. The flatness is achieved by optimizing the doping concentration and Fermi level (FL) of the surrounding layers. Results show that the maximum 44.12% efficiency can be achieved under maximum optical intensity. Keywords: Solar cell, Quantum dot, Flat intermediate band, Quantum efficiency, Fermi energy level, Doping concentration