Martin Ntwaeaborwa
University of the Free State, Bloemfontein, South Africa
Title: Lanthanides doped upconversion metal oxide nanocomposites for solar cell application
Biography
Biography: Martin Ntwaeaborwa
Abstract
There has been a growing demand to develop low cost but effi cient solar cell devices either to compete on an equal footing basis or to replace conventional multicrystalline photovoltaic cells. Th is has called for development of new advanced materials, new generation and confi guration of solar devices. Because of this, photovoltaic industry has, in the past few decades, experienced
rigorous transformation where traditional solar cells formed by compact semiconductor layers have been joined by new kinds of cells constituted by complex mixture of organic, inoroganic and solid or electrolyte materials and rarely rely on charge separation at nanoscale. In addition, new materials based on a combination of large bandgap semiconducting metal oxide, ceramic and metal oxide/sulfi de nanocomposites that are transparent and conductive and have low electrical resistance are being developed to improve the power conversion effi ciency of the new generation of solar cell devices. We synthesized rare-earths (Er3+, Tm3+, Yb3+) doped Al2O3-TiO2 metal oxide nanocomposites and examined their structure, particle morphology and photoluminescent properties. We demonstrated the intense infrared to visible upconverted luminescence in Al2O3-TiO2 co-ativated with Er3+-Tm3+ and Er3+-Yb3+ when excited using the fi bre coupled 980 nm laser. The mechanism responsible for upconversion that involves the sequential two photon absorption will be discussed. These materials were evaluated for use as upconversion layers in solar cells.