Improved efficiency of plasmonic tin sulfide solar cells

Solar cells with the structure ITO–PEDOT:PSS–Ag:SnS–Al were fabricated with the active layer of tin sulphide with silver nano-particles (Ag:SnS) grown by thermal co-evaporation. To understand the influence of the silver nanoparticles on the energy conversion process, cells with varying active layer thicknesses were compared experimentally and theoretically with corresponding pristine ITO–PEDOT:PSS–SnS–Al cells . Experimental results showed that the Ag nanoparticles act as scattering centers, resulting in longer optical path lengths for incident light. Theoretically we have shown that this in turn results in more charge carriers being generated and thus enhancing the efficiency of the structure as compared to the pristine ITO–PEDOT:PSS–SnS–Al structure. The fabricated plasmonic solar cells of SnS showed an improvement in efficiency of more than 67 %. The results are encouraging and suggests more concerted effort needs to be made on SnS.