Dual spectral matching in perovskite solar cells via upconverting plus downshifting nanoparticles

Abstract

Maximizing the efficiency of solar cells is a key step toward advancing photovoltaic technologies and fully harnessing the energy conversion potential of sunlight. This study investigates the incorporation of core–shell nanoparticles (NPs) NaGdF4:Yb3+

,Tm3+@NaGdF4:Eu3+

(TMN) and

NaGdF4:Yb3+

,Er3+@NaGdF4:Eu3+

(ERN) into perovskite solar cells (PSCs) with the aim of enhancing their power conversion efficiency. The NPs were synthesized via thermal decomposition and characterized using a set of techniques, including photoluminescence spectroscopy, quantum yield measurements, transmission electron microscopy, X-ray diffraction, solar simulator-based efficiency measurements, and external quantum efficiency evaluations. The lanthanide-doped NPs exhibited intense downshifting luminescence and weaker upconversion emission, acting as spectral converters that transform poorly absorbed regions of the solar spectrum into wavelengths usable by the device. Devices containing ERN NPs showed a relative increase of 22.19% in power conversion efficiency, whereas those with TMN NPs exhibited an improvement of 13.23%. These gains are primarily attributed to the efficient downshifting emission of Eu3+

and the superior surface passivation provided by the core–shell architecture. Together, these mechanisms suppress recombination losses and optimize charge carrier dynamics. These results highlight the potential of lanthanide-based photon-converting materials to overcome the intrinsic spectral absorption limitations of PSCs, presenting a promising strategy for the development of next-generation photovoltaic technologies.