Metal Coordination Complexes: A Bottom-Up Approach Tailored Towards Solar Energy Applications

Luminescent downshifting (LDS), a passive design approach, focused on improving the short-wavelength response of photovoltaic technologies through the application of retrofitted photoluminescence layers has undergone a recent renaissance. Previously limited by the lack of viable candidates, the recent advancements in synthetic chemistry and nanomaterials have renewed interest in the once dormant application. In this work, a series of 30 phenanthroline-based heteroaromatic ligands were evaluated in terms of their optical properties and suitability for LDS applications. Three of the materials fulfilled the criteria for inclusion in LDS devices, displaying luminescent quantum yields in the range of 0.80–0.95: with the structures absorbing heavily over the 300–500 nm range. Given the active role of ligands in sensitizing metal coordination centres, during the formation of coordination complexes, the ligands catalogued and evaluated herein could provide a welcome breath of renewed interest in the application of LDS layers to a range of commercial and noncommercial photovoltaic technologies. Other molecules within the family of ligands catalogued, showcased a large degree of non-radiative energy transfer, making them potential candidates for solar thermal applications, whereby localized heat generation and transfer is a favourable consideration.