Surface passivation of silicon nanostructures for high efficiency hybrid solar cells
Date of Issue2016
School of Electrical and Electronic Engineering
As a renewable and environmentally-friendly energy, solar energy can effectively avoid the destruction and pollution of environment caused by the conventional approaches. In order to obtain high efficiency and low cost, many different types of solar cells have been actively developed. The SiNW/PEDOT:PSS hybrid solar cell is thought to have great potential because of its good light trapping capability, high power conversion efficiency and simple manufacturing process.In this report, we design a passivation treatment process which can enhance the performance of the SiNW/PEDOT:PSS hybrid solar cell. The dissertation is divided into two parts. In the first part, both the basic principle of solar cell and characteristics of the silicon nanowire structure are introduced. Following that, the development history of silicon nanowire arrays solar cells and the working mechanism of passivation are presented. The second part mainly describes the solar cell fabrication process in the work and the additional surface passivation treatment in detail. Based on the analysis and comparison of the experimental results, the effects of surface passivation on the device performance are then explained.The proposed surface passivation treatment consists of two steps. First, silicon nanowires are subjected to UV-ozone treatment at low temperature to form an ultrathin layer of oxide. A portion of the oxide layer is then removed by HF etching at the second step. This process can remove the silver nanoparticles adhering at the surface of the silicon nanowires, which are produced in the process of metal-catalyzed etching. At the same time, it can also reduce the surface defect density, thereby reducing the carrier recombination rate. Overall, surface passivation treatment can increase power conversion efficiency of the solar cells from 8.21% to 12.19%.
DRNTU::Engineering::Electrical and electronic engineering