A facile inexpensive route for SnS thin film solar cells with SnS2 buffer

Environment-friendly SnS based thin film solar cells with SnS2 as buffer layer were successfully fabricated from a facile inexpensive route, chemical bath deposition (CBD). Layer studies revealed that as-grown SnS and SnS2 films were polycrystalline; (1 1 1)/( 0 01) peaks as the preferred orientation; 1.3 eV/2.8 eV as optical band gaps; and showed homogeneous microstructure with densely packed grains respectively. Ionization energy and electron affinity values were found by applying photoemission yield spectroscopy (PYS) to the CBD deposited SnS and SnS2 films for the first time. These values obtained as 5.3 eV and 4.0 eV for SnS films; 6.9 eV and 4.1 eV for SnS2 films. The band alignment of SnS/SnS2 junction showed TYPE-II heterostructure. The estimated conduction and valance band offsets were 0.1 eV and 1.6 eV respectively. The current density-voltage (J-V) measurements of the cell showed open circuit voltage (V-oc) of 0.12 V, short circuit current density (Jsc) of 10.87 mA cm(-2), fill factor (FF) of 39% and conversion efficiency of 0.51%. (C) 2016 Elsevier B.V. All rights reserved.