LOW COST AND HIGH EFFICIENCY SILICON NANOWIRE BASED SOLAR CELL

Abstract

Recently nanomaterials like Nanowire (NW), nanoparticle and quantum dot have shown to have enormous characteristics like lager surface to volume ration, quantum confinement effect that can be exploited by using them as an active element in the solar cells. NW structured solar cells have shown promising potential for integrated power source for Nano electronics systems such as driving element for nanowire sensors, logic gates This thesis shows the description and exploration of unique solar cell design concept namely the radial p-n junction, Nano/micro wire array solar cell which reduces the production cost by ten times. Such design potentially enable a separate optimization of the design requirements for the light absorption and carrier extraction, which are two main necessary condition for efficient energy conversion in photovoltaic device. The main idea of getting higher efficiency arises due to the orthogonalized charge separation i.e. charge carrier created due to the incident light get separated normal to the incident light which can be easily collected and allow to use low grade silicon without compromising with the efficiency. SiNWs for the solar cell can be grown with top down or bottom up method, but many method uses very sophisticated instrument to grow SiNWs, though the metal assisted chemical etching can be used to grow the controlled length SiNWs at room temperature without using sophisticated instrument but still diameter controlling is difficult task. So, in thesis we have shown a new method to grow controlled length and diameter SiNWs using chemical etching process. Also we have simulated current transportation equation for the p-n radial junction, which show that by optimizing the length and diameter of SiNWs appreciable efficiency can be obtain at various defect density, which shows that low grade material can be used SiNWs based solar cell