Patterning of nanopillars-based CdS/CdTe thin films for photonic applications

In this study we propose a new design to place the contacts for both p-type and n-type semiconductors at the bottom of solar cell to increase photons entering the absorber layer. The fabricated device contains periodic nanopillars of similar to 243 nm radius and centre to centre pillar distance of similar to 550 nm. In addition to the fabrication, thin films of n-CdS and p-CdTe have been characterised for their material properties at different annealing temperatures in this study. The X-ray diffraction pattern for CdTe and CdS revealed that the growth is preferentially along the (111) plane with a cubic zinc blend and cubic structure, respectively. Optimum absorption of the solar spectrum for a single junction solar cell occurs with the optical band gap of 2.36 eV for CdS and 1.45 eV for CdTe. The significance of the work creates a new beginning for the fabrication of textured thin film photovoltaic cell