Ultraviolet spectrum downshifting in polymer nanocomposite films for the enhancement of optoelectronic devices

Abstract

We report on polymer nanocomposite films with ultraviolet (UV) spectrum down-shifting that can be transferred using the open-air multi-beam multi-target pulsed laser deposition (MBMT-PLD) on opto-electronic devices, such as photovoltaic (PV) cells, for the enhancement of their performance. The nanocomposites were made of the space-grade polymer CORIN impregnated with nanoparticles (NPs) of rare-earth (RE) doped compound NaYF 4 : Eu 3+ . NPs had a peak of down-shifted photoluminescence (PL) at 623 nm and a PL quantum yield (PLQE) of ~ 50%. The enhancement of the coated PV cells was two-fold: (a) protection from harmful solar UV radiation and (b) the increase of the PV conversion efficiency. We describe the results of characterization of the NPs using dynamic light scattering, X-ray diffraction, and optical spectroscopy. The nanocomposite films were deposited on Silicon heterojunction (SHJ), Copper-Indium-Gallium-Selenide (CIGS) and inverted metamorphic multijunction (IMM) solar cells. The cells were exposed to 365-nm UV radiation from a light emitting diode (LED). The I-V characteristics of the cells were measured with a solar simulator using AM0 filter. The proposed films improved UV stability of all three cell types: the power degradation significantly slowed down, CIGSs (by half). The proposed films have great commercial potential, especially for the applications to space power.