In2S3 ZnS CdS assisted photosensitization of mesoporous TiO2

Abstract

One of the important energy sources considered for the next generation with renewable and clean energy characteristics is the solar energy where light i.e. photons with concrete energies are converted into electricity. Optimum power conversion efficiency so far reported using dye-sensitized solar cells is as high as 12% where natural and Ru-based dyes are used as sensitizers. Nevertheless, the key problem to achieve higher PCE in nanostructured electrodes remains unaddressed. Two of the major limiting factors for PCE in DSSCs is the transport of photogenerated electrons through the randomized network of semiconductor nanoparticles electrode that eventually recombine and the uncontrolled oxidation of organometallic sensitizer. Replacement of semiconductor nanoparticles by 1D nanostructure can find one of the effective ways to smoothen the transport of photogenerated electrons. This is to replace as they provide direct electrical pathways for the photogenerated carriers. Several efforts have been made in the development of 1D material for application in solar cells. Moreover, such 1D nanostructure provides high junction areas and low reflectance owing to their ability to scatter and trap light. Secondly, to address the issue of organometallic sensitizers that are susceptible to oxidation, quantum dots (QDs) or crystallites are quite promising alternatives, as they prominently possess intrinsic properties such as tunable band gap, high extinction coefficient and large intrinsic dipole moment etc. Thus, quantum dot-sensitized photoelectrochemical cells are of particular interest in the development of environmental friendly energy source due to their facile fabrication processes, low-cost and theoretical estimation of high efficiency. Various QDs, such as CdS, CdSe, In2S3, ZnS, PbS, PbSe, InP etc., has been demonstrated. newline