TiO2 nanorod arraysfunctionalized with In2S3 shell layer by a low-cost route for solar energy conversion

Abstract

We report the fabrication and characterization of aTiO2–In2S3 core–shellnanorod array structure for application of semiconductor-sensitized solar cells. Hydrothermally synthesizedTiO2 nanorod arrays on FTO glass substrates are functionalized with a uniformIn2S3 shell layer by using the successive ion layer adsorption and reaction(SILAR) method. This low-cost technique promotes a uniform deposition ofIn2S3 nanoshells onthe surface of TiO2 nanorods, thus forming an intact interface between theIn2S3 shell andTiO2 core. Results showthat the thickness of In2S3 shell layers as well as the visible light absorption threshold can be effectivelycontrolled by varying the coating cycles during the SILAR process.The best reproducible performance of the sandwich solar cell using theTiO2–In2S3 core–shellnanorod arrays as photoelectrodes was obtained after 30 SILAR cycles, exhibiting a short-circuit current (Isc) of 2.40 mA cm − 2, an open-circuitvoltage (Voc) of 0.56 V, a fill factor (ff) of 0.40 and a conversion efficiency (η) of 0.54%, respectively. These results demonstrate a feasible and controllable route towardsIn2S3 coating on a highly structured substrate and a proof of concept that suchTiO2–In2S3 core–shell architectures are novel and promising photoelectrodes in nanostructured solarcells.