Tuning the plasmonic absorption of metal reflectors by zinc oxide nano particles: Application in thin film solar cells

The short circuit current and conversion efficiency of silicon thin film solar cells can be increased by efficient light trapping. The short circuit current is maximized if the metal back contact of the solar cells efficiently scatters and diffracts the reflected light, while optical (plasmonic) losses in the back contact are minimized. The investigations show that the optical losses in the back contact are highest if nano features are present at the dielectric/metal interface. However, large back contact features with dimensions comparable to the optical wavelength efficiently scatter and diffract the reflected light. In this study the morphology of the back contact was controlled by inserting zinc oxide nano particles. The influence of the nano particles on the quantum efficiency, short circuit current and conversion efficiency is studied.