Improving the Optical Efficiency and Concentration of a Single-plate Quantum Dot Solar Concentrator using Infra-red Emitting Quantum Dots
Document Type Article
Published in Solar Energy, Vol.83, No. 7, pp.978-981, 2009 Available from http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6V50-4VH7BDF-1-F&_cdi=5772&_user=2322584&_orig=browse&_coverDate=07%2F31%2F2009&_sk=999169992&view=c&wchp=dGLzVlz-zSkWz&md5=ad75ddf70416fecfd5e96ee21e9bff28&ie=/sdarticle.pdf
Low luminescent quantum yields and large overlap between quantum dot (QD) emission and absorption spectra of present commercially-available visible-emitting QDs have led to low optical efficiencies for single-plate quantum dot solar concentrators (QDSCs). It is shown that using near infra-red (NIR) emitting QDs, re-absorption of QD emitted photons can be reduced greatly, thereby diminishing escape cone losses thus improving optical efficiencies and concentration ratios. Using Monte-Carlo ray-trace modelling, escape cone losses are quantified for different types of QD. A minimum 25% escape cone loss would be expected for a plate with refractive index of 1.5 containing QDs with no spectral overlap. It is shown that escape cone losses account for not, vert, similar57% of incident photons absorbed in QDSCs containing commercially-available visible-emitting QDs.