Excellent facilities have been developed to prepare and characterize thin film solar cells on SiO2metallic foil. A detailed literature search is being carried out on the various materials to be used as quantum dots. An efficiency of 10.4% (AM 1.5) has been achieved without any intermediate layer of quantum dots. Research is being initiated on the preparation of quantum dots by depositing these quantum dots through a porous alumina membrane.

Quantum dot or quantum well solar cells employ an intermediate band of allowed energies in the forbidden bandgap so as to benefit from the excitation of electrons from the valence band to the conduction band using two of lower energy photons. This concept has shown slight improvement of efficiency in (GaAl)As cells. Again, the efficiency is not higher than that of a conventional GaAs cell. Thus the quantum dot solar cell concept is interesting and may turn out to be useful for achieving very high efficiencies. The best course would be to understand the fundamental limitations of each concept and to find ways to overcome them in an evolutionary fashion. Moreover, a multi-pronged approach allows developing several technologies, comparing the results at each stage and fine-tuning the approach to achieve the best results in the shortest possible period.