Cellulose nanocrystals as host matrix and waveguide materials for recyclable luminescent solar concentrators

The use of luminescent solar concentrators is a cost-effective approach that can efficiently concentrate direct and diffused sun light without any optical components. In this work, the prospect of cellulose nanocrystals (CNCs), an ecofriendly biopolymer, as a host matrix and waveguide for luminescent solar concentrators (LSCs) has been studied. The results show that the CNC material as a host matrix will absorb more photons, ensuring more photoluminescence from organic dyes compared to acrylic polymer emulsion, a common host matrix material in LSCs. Due to the light scattering effect within the CNC material, optical efficiency of the fabricated device decreases once the distance between the point where light hits the sample and the edge, from where photons get collected by the integrating sphere, is increased. Thus optimization of CNC film processing is required if the CNC film is used as a waveguide in LSCs. However the higher optical efficiency of CNC samples compared to acrylic polymer emulsion samples at shorter distances suggests its superior quality as a host matrix. A recyclability study reveals that the CNC material can be reused without compromising device quality, unlike acrylic polymer emulsion samples, which makes it a good candidate as an ecofriendly material for low cost, large scale manufacturing of luminescent solar concentrators.