Fabrication of SnS quantum dots for solar-cell applications: Issues of capping and doping (Phys. Status Solidi B 7/2014)

SnS quantum dots have great potential for photovoltaic applications because they consist of non-toxic and environmentally benign material, making them most suitable for use in consumer products such as solar panels. The synthesis of this type of nanostructure is carried out by a colloidal approach at room temperature under nitrogen atmosphere. By proper selection of the solvent it is possible to modify the shape of the nanoparticles from nanorods to spherical or square structures (see the cover image). This is due to the preferential orientation of the alkyl groups of the TOPO capping with respect to the solvent. By modifying the shape and the size the band gap and optical properties can be tuned. SnS material has already been used in solar cell devices as absorber layer for heterojunction devices. In the article by Jatin K. Rath et al. (pp. 1309–1321) a third generation solar cells fabrication scheme is proposed, in which an intermediate band gap layer is incorporated in a CIS solar cell to increase its current generation. This opens the way to improving the performance of low-cost chalcogenide-based solar cells in general. The defect passivation, using either TOPO or a core-shell structure, as well as the mechanism of doping the particles are highlighted.