Overview
The present invention provides a novel bottleneck nanopillar type assembly of n- and p-type semiconducting material from II-VI group and a method for fabrication thereof. The variation in the diameter of the nanopillars is in the range of quantum confinement region, so as to maximize the optical absorption of the solar spectrum in a wide range and simultaneously reducing the reflectivity to minimum. Bottleneck design of the device also aids in efficient charge extraction by forcing the electrons and holes to flow through n- and p-type regions respectively.