Renewable Energy Future

INTRODUCTION The major challenges for mankind in the upcoming years include the availability of fossil fuels and global warming that result from their ever increasing use. The population growth and today’s modern life styleare the root cause for the strong energy demand. Since thedemand for the energy rises day by day and enforce the scientific community to explore the potential of renewable sources of energy for the future. Renewable energy is energy which is generated from natural sources i.e. sun, wind, rain, tides and it is the by far most the cleanest sources of energy available on this planet. Among the various energy sources the solar energy is an attractive alternative energy source, inexhaustible, available at no cost and pollution

The photovoltaic effect was first discovered by Becquerel [1] in 1839 who observed a photovoltage when light was directed onto one of the electrodes in an electrolyte solution. Later Lange [2] et.al did pioneering work on selenium and cuprous oxide photovoltaic cells. Today photovoltaic modules are incredibly the prime source of power for satellites. Moreover the present day single crystalline solar cells are costly. So a substantial reduction in the cost is needed at this juncture for the effective photovoltaic utilization for terrestrial applications. But the thin film solar cells require only small amount of expensive semiconductor materials and therefore they can be considered as best energy harvesting technology. The current emphasis in photovoltaic is directed toward thedevelopment of high performance, inexpensive, stable thin film solar cells that canserve in the long run as a viable alternative to single crystal silicon

Growth of semiconducting oxides is getting attraction of scientific community because of its high optical transparency, thermal and chemical stability, and easy deposition methods. Whereas cupric oxide (CuO) is a p-type semiconductor with a bandgap of ~1.5 eV with the theoretical maximum conversion efficiency of ~20% [5].There are several research groups have reported to improve the performance of the CuO-based solar cells, butVoc and Iscremained low. Further the Carrier loss by recombination is also one of themajor lossmechanisms, which limits the performance of the device in copperoxide-based solar cells. However, the origin and effect of the charge carrier recombination are not yet well identified. Even though CuO is a very promising material for solar cells application, there are only a few reports available on CuO-based solar cells [6-8]. In this work, we have demonstrated p-CuO/n-Si heterojunction solar cells by using a SILAR technique. An improvement in the performance of p-CuO/n-Si heterojunction solar cells was observed through optimization of preparation conditions. Furthermore, the impact of adsorption time, reaction temperature, solution pH and molarity during deposition on the material quality, structural, microstructure,composition, optical and electrical properties of CuO-based solar cells have been investigated in