Electrodeposition of Lithium-Based Upconversion Nanoparticle Thin Films for Efficient Perovskite Solar Cells

In this work, high-quality lithium-based, LiYF4=Yb3+,Er3+ upconversion (UC) thin film was electrodeposited on fluorene-doped tin oxide (FTO) glass for solar cell applications. A complete perovskite solar cell (PSC) was fabricated on top of the FTO glass coated with UC thin film and named (UC-PSC device). The fabricated UC-PSC device demonstrated a higher power conversion efficiency (PCE) of 19.1%, an additional photocurrent, and a better fill factor (FF) of 76% in comparison to the pristine PSC device (PCE = ~16.57%; FF = 71%). Furthermore, the photovoltaic performance of the UC-PSC device was then tested under concentrated sunlight with a power conversion efficiency (PCE) of 24% without cooling system complexity. The reported results open the door toward efficient PSCs for renewable and green energy applications

High-Performance and Stable Perovskite Solar Cells Using Carbon Quantum Dots and Upconversion Nanoparticles

Upconversion nanoparticles (UCNPs) and carbon quantum dots (CQDs) have recently received a lot of attention as promising materials to improve the stability and efficiency of perovskite solar cells (PSCs). This is because they can passivate the surfaces of perovskite-sensitive materials and act as a spectrum converter for sunlight. In this study, we mixed and added both promising nanomaterials to PSC layers at the ideal mixing ratios. When compared to the pristine PSCs, the fabricated PSCs showed improved power conversion efficiency (PCE), from 16.57% to 20.44%, a higher photocurrent, and a superior fill factor (FF), which increased from 70% to 75%. Furthermore, the incorporation of CQDs into the manufactured PSCs shielded the perovskite layer from water contact, producing a device that was more stable than the original

Halide Versus Non‐Halide Salt: Effect of Guanidinium Salts on the Structural, Morphological, and Photovoltaic Performance of Perovskite Solar Cells

We comparatively analyzed the impact of halide and non-halide sources of guanidinium cations, including guanidinium chloride ((NH2)3CCl = GCl) and guanidinium thiocyanate ((NH2)3CSCN = GTC) on the structural, morphological and photophysical properties of (CsMAFA)PbBrxI3-x (x=0.17) (MA= methylammonium, FA= formamidinium)precursor solution does not influence the perovskite structure, however, the formation of photoinactive phases is found to be dependent on the nature of counterion (halide vs non- halide). Furthermore, morphological analysis shows that with the addition of guanidinium salts, the apparent grain size decreases due to the enhancement in nucleation density and/or slow growth of perovskite structures. More importantly, the introduction of GCl led to the fabrication of perovskite solar cells (PSCs) yielding photovoltage as high as 1.16 V (1.1 V for reference). By contrast, the introduction of GTC minimally affected the photovoltage underlining the significance of counterion in improving the photovoltage of PSCs. We also present preliminary results of our DFT based theoretical investigation related to the effect of G cation on the structure of perovskite system. In summary, the insights gained through structural, and morphological characterization helped to understand the critical role of counterions of guanidinium salts in PSCs

Lithium-Based Upconversion Nanoparticles for High Performance Perovskite Solar Cells

In this work, we report an easy, efficient method to synthesize high quality lithium-based upconversion nanoparticles (UCNPs) which combine two promising materials (UCNPs and lithium ions) known to enhance the photovoltaic performance of perovskite solar cells (PSCs). Incorporating the synthesized YLiF4:Yb,Er nanoparticles into the mesoporous layer of the PSCs cells, at a certain doping level, demonstrated a higher power conversion efficiency (PCE) of 19%, additional photocurrent, and a better fill factor (FF) of 82% in comparison to undoped PSCs (PCE = ~16.5%; FF = 71%). The reported results open a new avenue toward efficient PSCs for renewable energy applications