M. Thambidurai

High performance inverted organic solar cells with solution processed Ga-doped ZnO as an interfacial electron transport layer

We demonstrate solution-processed Ga-doped ZnO incorporated as an interfacial electron transport layer into inverted organic solar cells with active layers comprising either PCDTBT or PTB7 mixed with PC71BM. The 5.03 at% Ga-doped ZnO showed the best efficiencies of 5.56% and 7.34% for PCDTBT and PTB7 polymers respectively.

One step synthesis, optimization and growth mechanism carambola fruit shaped CuO nanostructures: electrochromic performance

Micro and nanostructures with well-defined shape have attracted great interest due to their novel properties and diverging applications. Herein the one step simple sonochemical method for the synthesis of carambola fruit shaped and spindle shaped semiconducting copper oxide nanostructures are described. The pH concentration and the reaction time have been varied in order to find the optimized condition in which spindle shaped and carambola fruit shaped CuO nanoparticles are obtained. Also the effect of pH and reaction time on the properties of CuO nanostructures have been investigated and reported. The possible growth mechanism for the carambola fruit shaped structures has also been discussed. The prepared samples have been characterized using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and UV–visible spectrophotometry.

Nanostructured Electron-Selective Interlayer for Efficient Inverted Organic Solar Cells.

We report a unique nanostructured electron-selective interlayer comprising of In-doped ZnO (ZnO:In) and vertically aligned CdSe tetrapods (TPs) for inverted polymer:fullerene bulkheterojunction (BHJ) solar cells. With dimension-controlled CdSe TPs, the direct inorganic electron transport pathway is provided, resulting in the improvement of the short circuit current and fill factor of devices. We demonstrate that the enhancement is attributed to the roles of CdSe TPs that reduce the recombination losses between the active layer and buffer layer, improve the hole-blocking as well as electron-transporting properties, and simultaneously improve charge collection characteristics. As a result, the power conversion efficiency of PTB7:PC70BM based solar cell with nanostructured CdSe TPs increases to 7.55%. We expect this approach can be extended to a general platform for improving charge extraction in organic solar cells.