Effect of vacuum annealing on structural, morphological and optical properties of Sn2Sb2S5 thin films with different thicknessesNawel Khedmi, Mohamed Ben Rabeh, Fethi Aousgi and Mounir KanzariEur. Phys. J. Appl. Phys., 69 1 (2015) 10303DOI: https://doi.org/10.1051/epjap/2014140266