Linker free synthesis of TiO2/Bi2S3 heterostructure towards solar cell application: Facile chemical routes

Titanium dioxide/bismuth trisulphide (TiO2/Bi2S3) heterostructures are synthesized in a linker free synthesis approach which consists of a facile spin coating method followed by a successive ionic layer adsorption and reaction (SILAR) at room temperature (27 °C). These TiO2/Bi2S3 thin films are characterized by using different techniques. X-ray diffraction and high resolution transmission electron microscopic studies confirm the formation of layered heterostructures. Surface morphological analysis confirmed the uniform coverage of tiny Bi2S3 particles on TiO2 surface. Further, quantum size effect is observed by using the optical absorption studies. Finally, sandwich type devices are constructed and photovoltaic parameters are investigated in the illumination of standard 1 sun condition [AM 1.5G, 50 mW/cm2] and the photovoltaic parameters are discussed herein. In addition to this the effect of different number of Bi2S3 SILAR cycles on photovoltaic parameters has been investigated.