Patterned dye structures limit reabsorption in luminescent solar concentrators

Shufen Tsoi,Dirk J Broer,Michael G Debije,Cees W Bastiaansen

doi:10.1364/oe.18.00a536

Abstract

This work describes a method for limiting internal losses of a luminescent solar concentrator (LSC) due to reabsorption through patterning the fluorescent dye doped coating of the LSC. By engineering the dye coating into regular line patterns with fill factors ranging from 20 - 80%, the surface coverage of the dye molecules were reduced, thereby decreasing the probability of the re-emitted light encountering another dye molecule and the probability of reabsorption. Two types of fluorescent dyes with different quantum yields were used to examine the effects of patterning on LSC performance. The effect of various dimension and geometry of the patterns on the efficiency and edge emission of LSC are presented and analyzed.

Highlights

Photovoltaic (PV) solar concentrators using reflective or refractive optics coupled to a suntracking system are promising methods for reducing the cost of solar energy, in the form of large solar farms or power plants [1]
This work describes a method for limiting internal losses of a luminescent solar concentrator (LSC) due to reabsorption through patterning the fluorescent dye doped coating of the LSC
By engineering the dye coating into regular line patterns with fill factors ranging from 20 - 80%, the surface coverage of the dye molecules were reduced, thereby decreasing the probability of the re-emitted light encountering another dye molecule and the probability of reabsorption

Summary

Introduction

Photovoltaic (PV) solar concentrators using reflective or refractive optics coupled to a suntracking system are promising methods for reducing the cost of solar energy, in the form of large solar farms or power plants [1]. A main factor limiting LSC efficiency is internal losses due to reabsorption of light emitted by the dye molecules. Attempts have been made to increase the Stokes shift of the emitting material by replacing the fluorescent dyes with quantum dots [12, 13, 18, 19], lanthanide complexes [11], or by doping the dye molecules with materials such as thionin [14] While these alternate luminophores allow better control of the Stokes shift of the luminescent material, the materials suffer from either low quantum yields or poor light absorption when compared to organic fluorescent dyes such as perylenes [15]. Decreasing surface area coverage reduces the probability of interaction between re-emitted photons and dye molecules, and thereby minimizing reabsorption losses (see Fig. 1 for the concept behind the patterned layers)

Substrate Preparation

Sample Fabrication

Sample Characterization

Conclusion