Reabsorption Losses in Luminescent Solar Concentrators: Effect of the Band Gap of Semiconductor Quantum Dots, their Size and Dispersion A.I. Shkrebtii, A.V. Sachenko, I.O. Sokolovskyi, V.P. Kostylyov, M.R. Kulish and D.V. Khomenko 2017/04/25

Abstrac

We investigate the effect of semiconductor quantum dots (QDs) radius r and its dispersion ƒ´ r on the reabsorption during a luminescence process. QDs are promising as chromophores in luminescence solar concentrators (LSCs). To minimize detrimental reabsorption losses, six semiconductors, typically used to fabricate QDs, with a wide range of the bulk bandgaps Eg0 have been considered: CdS (Eg0 = 2.42 eV), CdSe (Eg0 = 1.67 eV), CdTe (Eg0 = 1.5 eV), InP (Eg0 = 1.27 eV), InAs (Eg0 = 0.355 eV), and PbSe (Eg0 = 0.27 eV). We prove that by adjusting the QD radius r and dispersion ƒ´r, it is possible to optimize nanocrystal dimensions to minimize the
reabsorption. It was shown that for the semiconductor bulk band gap range between 2.42 eV to 1.27 eV there is always the optimum QD size and its dispersion, at which the reabsorption is below the total experimental error of the measured normalized both absorption coefficient and luminescence intensity. Further reduction of Eg0 increases the reabsorption at any values of r and ƒ´ r: for instance, for PbSe based QD with Eg0 =0.27 eV, 1 nm mean radius and its 1% dispersion, the reabsorption reaches 54%. We estimate the width of the part of the solar spectrum, from which the photons contribute to the luminescence processes. This is important for several LSCs, stalked on top of each other.

Authors and affiliations

A.I. Shkrebtii(1), A.V. Sachenko(2), I.O. Sokolovskyi(2), V.P. Kostylyov(2), M.R. Kulish(2), and D.V. Khomenko(2)
1. University of Ontario Institute of Technology, Oshawa, Ontario,Canada
2. V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, Ukraine

Key word

Photoluminescence, quantum dots, luminophore, reabsorption, solar cells, efficiency, concentrator.

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