Rational Design of Solar Cells for Efficient Solar Energy Conversion

12Hot Electrons Role in Biomolecule‐based Quantum Dot Hybrid Solar Cells

T. Pazhanivel¹, G. Bharathi², D. Nataraj², R. Ramesh³, and D. Navaneethan³

¹ Department of Physics, Periyar University, India

² Department of Physics, Bharathiyar University, India

³ Department of chemistry, Periyar University, India

12.1 Introduction

Solar cells are devices that convert solar light into electrical energy via a photovoltaic effect. The development of novel solar cells is being promoted by the increasing awareness that available energy reserves are running out. A major energy shortage is expected in the near future unless renewable energy can cover the deficit. On the other hand, the supply of energy from the sun is 3 × 1024 joules per year, about 10 000 times more than current annual consumption. In other words, covering 0.1% of the earth’s surface with solar cells with an efficiency of 10% would satisfy our present needs. Crystal silicon based solar cells are the mainstream of the current photovoltaic industry. But the relatively thick layer of silicon required for reasonable photon capture rates and the high expense of crystal silicon fabrication is a heavy burden. Other approaches including changes in the material side (amorphous silicon) and the device side (thin film, multiple junctions) still cannot satisfy the requirement of high efficiency and low cost simultaneously. In one word, solar cells cannot be employed as the main power source for human beings until a significant breakthrough ...