CHARACTERISATION OF SPECTRAL SHIFTING PROPERTY OF FLUORESCENT CORE-SHELL ZnS:Mn NANOPARTICLES DISPERSED IN A POLYMER MATRIX

摘要

Luminescent nanoparticles can be used to alter the intensity distribution with respect to wavelength ofincident sunlight. This strategy is anticipated to help improve solar cell performance in the low wavelength range. Apossible candidate for such a luminescent down-shifter is manganese-doped zinc sulphide nanoparticles. Thesenanoparticles were synthesised by a chemical route to investigate their optical properties and stability. They areintended for future coupling with a silicon solar cell to bring about enhanced efficiency, translating to a lower costper watt. Synthesized ZnS nanoparticles with 10% manganese doping were protected by ZnS shells, introduced by anovel ultrasonication method. The core-shell nanoparticles were further dispersed in a polyphosphate matrix forenhanced fluorescence and long-term stability. Prepared samples were characterized by UV-Visible absorptionspectroscopy, fluorescence spectrometry, X-ray diffractometry and transmission electron microscopy. A comparisonof fluorescence from freshly prepared and five-month old samples clearly demonstrated increased stability in thepresence of the polyphosphate matrix. Further work is required to investigate whether optical properties of thenanoparticles can be controlled suitably for application as luminescent down-shifters to boost silicon PV cellefficiency.