Cost-effective solar concentrators based on red fluorescent Zn(ii)–salicylaldiminato complex

Abstract

Sunlight concentration is a promising path to cost-effective photovoltaic (PV) technologies. Compared to standard concentrators based on geometrical optics, luminescent solar concentrators (LSCs) appear to be viable and convenient alternatives because sunlight concentration to PV occurs with diffuse light and there is no need for sun tracking or cooling apparatuses. In this study, we report on the optical efficiencies of luminescent solar concentrators (LSCs) based on poly(methyl methacrylate) (PMMA) thin films doped with a red-emitting zinc(II) complex of the D–A–D type ligand N,N0-bis(2-hydroxy-1-naphthylidene)-diaminomaleonitrile (ZnL). ZnL is attractive for use in LSC owing to its easy and cheap synthesis. ZnL in PMMA shows an emission band at 624 nm, a Stokes shift of 34 nm and an average QY of 23%, data comparable to those recorded in solution and efficiently predicted by DFT calculations. A study of ZnL/PMMA LSC yields optical efficiencies of 7%, which is comparable to those based on the near unity QY fluorophores such as Lumogen Red. These performances were attributed to the higher emission redshift and larger Stokes shift of ZnL that prevent the loss of efficiencies due to self-absorption and possibly circumvent its lower QY

Luminescent solar concentrators: boosted optical efficiency by polymer dielectric mirrors

“…1(a)). So far, the lost photons have been recycled using different reflectors including diffusive back reflectors, complex mirroring systems using plasmonic structures, [17][18][19][20][21] rugate filters, or opal-like photonic crystals with photonic band gap (PBG) tuned on the emission spectrum. 19,[22][23][24] More recently, the role of front-and back-reflectors on the performances of LSCs has been modelled 25 and applied to LSCs embedding micro-solar cells into the waveguide.…”

On the Aggregation and Sensing Properties of Zinc(II) Schiff-Base Complexes of Salen-Type Ligands

“…Actually, ZnL complexes are generally emissive species, whose fluorescence is modulated by the structure of the bridging diimine [74]. Derivatives from Zn(salphen) [61,74,75,76,77] and Zn(salmal) [28,50,58,59,62,63,78,79] are those most investigated. Interesting, these complexes are characterized by very different fluorescent properties on switching from the aggregate species to the monomeric adducts.…”

“…Given the interesting photophysical characteristics of ZnL complexes, various studies have been done mainly involving derivatives of Zn(salmal) and Zn(salphen), in relation to their fluorescence in self-assembled mono- [80,81] or multilayers [82], in mesomorphic systems [32,33,34,35,83,84], for potential applications as dye sensitized solar cells [47,79,85], and with mechanochromic [86] and organogelation [46,86] properties.…”

Tuning the Fluorescence Emission and HOMO‐LUMO Band Gap in Homoleptic Zinc(II) Complexes with N,O‐Bidentate (Imidazo[1,5‐a]pyrid‐3‐yl)phenols

“…Also Schiff base ligands demonstrated to be useful for the synthesis of zinc(II) complexes with remarkable luminescence properties. Very recent examples are fluorescent zinc(II)‐salicylaldiminato compounds, dinuclear zinc salphen macrocycle complexes, and zinc(II) and cadmium(II) complexes with piperazino‐functionalized N , N′,O ‐tridentate ligands …”