Luminescent Down-shifting Research Articles

Transparent, Sprayable Plastic Films for Luminescent Down‐Shifted‐Assisted Plant Growth

AbstractThe world's steadily growing population and global heating due to climate change are a threat to food security. To meet this challenge, novel technologies are needed to increase crop production in a sustainable way. In this work, the use of luminescent down‐shifting (LDS) materials based on molecular Eu3+‐containing polyoxotitanates for plant growth enhancement is investigated. Using a systematic design strategy to optimize down‐shifting properties, conversion of the ultraviolet spectral range to the photosynthetically active radiation (PAR) is achieved with quantum yields as high as 68%. The prototype Eu3+‐compound can be incorporated into water‐based acrylic varnish that can be spray‐coated onto existing greenhouses. Comparing coated with uncoated greenhouses, basil plants produce 9% more leaf dry weight per plant, and a highly significant 10% increase in individual leaf dry weight. The coating reduces the amount of transmitted PAR by 8% but has advantageous effects on diffuse radiation and in reducing the internal mean temperature. Although there is some uncertainty as to the contribution of down‐shifting, with the bulk of the increase probably being due to higher diffused light and the reduction in maximum daily temperatures, this study establishes a model for the design of LDS paints for real‐world agricultural applications.

An Updated Review for Performance Enhancement of Solar Cells by Spectral Modification

Photovoltaic technology has become one of the major renewable ways to generate electric power. However, the mismatch between the incident solar spectrum and photo-electric response efficiency of solar cells severely constrains their performance. Hence, spectral modification technologies, e.g., up-conversion (UC), down-conversion (DC), and luminescent down-shifting (LDS) technologies have been applied widely in the photovoltaic field to reform the incident spectrum to match the best response band possible. In this paper, we review the latest developments of the three technologies above in terms of material selection, optical characteristics, and photovoltaic performance. It is found that the three most popular materials for conversion are NaYF4: Er3+, Yb3+, and Yb3+. The excitation bands for the three technologies are 800–1550 nm, 250–488 nm, and 250–488 nm, respectively, while the emission bands are 523–669 nm, 520–1031 nm, and 490–1010 nm, respectively. Furthermore, issues hindering the development of spectral modification technologies are pointed out, e.g., low absorption efficiency, poor quantum conversion efficiency, and hurdles in commercialization. Finally, suggestions and solutions to address the above-mentioned issues are provided.

Photon shifting and trapping in perovskite solar cells for improved efficiency and stability

Advanced light management techniques can enhance the sunlight absorption of perovskite solar cells (PSCs). When located at the front, they may act as a UV barrier, which is paramount for protecting the perovskite layer against UV-enabled degradation. Although it was recently shown that photonic structures such as Escher-like patterns could approach the theoretical Lambertian-limit of light trapping, it remains challenging to also implement UV protection properties for these diffractive structures while maintaining broadband absorption gains. Here, we propose a checkerboard (CB) tile pattern with designated UV photon conversion capability. Through a combined optical and electrical modeling approach, this photonic structure can increase photocurrent and power conversion efficiency in ultrathin PSCs by 25.9% and 28.2%, respectively. We further introduce a luminescent down-shifting encapsulant that converts the UV irradiation into Visible photons matching the solar cell absorption spectrum. To this end, experimentally obtained absorption and emission profiles of state-of-the-art down-shifting materials (i.e., lanthanide-based organic-inorganic hybrids) are used to predict potential gains from harnessing the UV energy. We demonstrate that at least 94% of the impinging UV radiation can be effectively converted into the Visible spectral range. Photonic protection from high-energy photons contributes to the market deployment of perovskite solar cell technology, and may become crucial for Space applications under AM0 illumination. By combining light trapping with luminescent downshifting layers, this work unravels a potential photonic solution to overcome UV degradation in PSCs while circumventing optical losses in ultrathin cells, thus improving both performance and stability.

Waste-derived carbon quantum dots for improving the photostability of perovskite solar cells to > 1,000 h

Power conversion efficiency (PCE) of perovskite solar cells (PSCs) has reached 26.1%, but PSC devices are plagued by poor stability when exposed to light (especially ultraviolet (UV) radiation), heat, and moisture. UV stability remains a significant challenge to overcome. Luminescent down-shifting (LDS) filters have shown significant enhancement in photostability and efficiency for PSCs. However, most explored LDS materials are costly, non-biodegradable, and the resulting photostability is limited to ∼100 h. In this report, as-obtained waste filtrate from the polyaniline (PANI) synthesis is used to synthesize fluorescent PANI carbon quantum dots (PANI-CQDs) using a facile hydrothermal method. Here we report, for the first time, the use of waste-derived PANI-CQDs to fabricate UV filters that are low-cost, bio-degradable, and room-temperature processible and, importantly, impart high UV and photostability to the PSCs. PSCs with these filters retained 90% and 100% of their initial performance when exposed to UV light and AM 1.5 solar radiation, respectively, for more than 900 h, while PSCs without filters degraded to 14 and 70% of their initial performance under the same conditions. Hence, we clearly show that using a waste-derived LDS filter improves the UV stability of PSCs by six times and photostability beyond 1,000 h.

Luminescent boron carbon oxynitride phosphors: a cost-efficient strategy to boost solar cell spectral responsiveness

The incorporation of a Luminescent down-shifting (LDS) layer has emerged as a compelling approach for augmenting the light absorption sensitivity and power conversion efficiency of solar cells, particularly in the short-wavelength light spectrum. In this investigation, we propose the utilization of low-cost, environmentally benign Boron carbon oxynitride (BCNO) phosphors as a viable material for the enhancement of solar radiation absorption in the ultraviolet-blue range. We synthesized BCNO phosphors through a combustion method and conducted a comprehensive analysis of the structural and spectral attributes concerning the impact of temperature. The synthesized boron carbon oxynitride phosphors exhibit a hexagonal boron nitride structure, with an irregular shape and an average particle size of 2447.9 nm. The analysis of photoluminescence spectra reveals that BCNO phosphors effectively capture photons within the 300–500 nm wavelength range and subsequently re-emit them at longer wavelengths. This phenomenon aligns with the overarching goal of optimizing solar cell performance, as it is in the longer wavelength range that solar cells exhibit enhanced efficiency. These findings support the promising potential of BCNO phosphors as a compelling choice for deployment as an LDS layer material on the periphery of solar cells. By facilitating increased photon absorption in the short-wavelength region, BCNO phosphors have the capacity to significantly enhance device performance.

New PMMA-InP/ZnS nanohybrid coatings for improving the performance of c-Si photovoltaic cells

Abstract Luminescent down-shifting (LDS) nanohybrid films are considered a potential solution to match the absorption spectrum of photovoltaic (PV) cells with the AM1.5 solar spectrum. LDS films were prepared by spin-coating polymethyl methacrylate (PMMA) doped with indium phosphide/zinc sulfide (InP/ZnS) quantum dots (QDs). The effect of doping concentration was investigated using X-ray diffraction, thermogravimetric analysis, transmission, and fluorescence spectroscopy. The results demonstrated that all PMMA LDS nanohybrid films were amorphous and exhibited thermal and chemical stability for all the doping concentrations of QDs. The optimal doping concentration was 0.06 wt%, demonstrating a tunable emission of the highest fluorescence quantum yield of 92% and the lowest reabsorption effect. This film showed the maximum enhancement of the efficiency of c-Si PV cells by 24.28% due to the down-conversion of ultraviolet A (UVA) portion of solar spectrum (320–400 nm) to match the sensitivity of c-Si PV cells. The implications of these results are significant for advancing affordable and clean energy in alignment with important sustainable development goals.

Polyvinyl Chloride-Based Luminescent Downshifting Film with High Flame Retardancy and Excellent UV Resistance for Silicon Solar Cells.

Solar power generation, as a clean energy source, has significant potential for development. This work reports the recent efforts to address the challenge of low power conversion efficiency in photovoltaic devices by proposing the fabrication of a luminescence downshifting layer using polyvinyl chloride (PVC) with added fluorescent dots to enhance light utilization. A photoluminescent microsphere (HCPAM) is synthesized by cross-linking hexachlorocyclotriphosphazene, 2-iminobenzimidazoline, and polyethyleneimine. Low addition of HCPAM can improve the fire safety of PVC films, raising the limiting oxygen index of PVC to 32.4% and reducing the total heat release and smoke production rate values by 14.5% and 42.9%, respectively. Additionally, modified PVC film remains a transparency of 88% and shows down-conversion light properties. When the PVC+1%HCPAM film is applied to the solar cell, the short-circuit current density increases from 42.3 to 43.8mAcm-2, resulting in a 7.0% enhancement in power conversion efficiency. HCPAM also effectively delays the photooxidative aging of PVC, particularly at a 3% content, maintaining the surface morphology and optical properties of PVC samples during ultraviolet aging. This study offers an innovative strategy to enhance the fire and UV-resistant performance of PVC films and expand their applications in protecting and efficiently utilizing photovoltaic devices.

Electrochromic windows based on luminescent acrylate/ionosilicas

AbstractPoly(methyl methacrylate) (PMMA)-based composite films doped with lanthanide-doped sol–gel derived imidazolium-based ionosilicas (IS-Ln) were recently proposed as active layers of luminescent down shifting (LDS) layers, but subsequent work demonstrated also their potential as electrolytes for electrochromic devices (ECDs) with foreseen application in smart windows of energy-efficient buildings. Nevertheless, some challenges remained to be addressed in the latter devices, the most critical one being the poor solubility of PMMA in the ionic liquid used in the formulation of these materials. To avoid this drawback, in the present work we propose novel lanthanide-containing acrylate/ionosilicas (AC/IS-Ln, Ln = Tb3+, Eu3+). The transparent, homogeneous, and luminescent hybrid materials synthesized are characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, atomic force microscopy, contact angle measurements, ionic conductivity, and photoluminescence spectroscopy. Optimized samples are successfully employed as electrolytes in luminescent ECD prototypes. The ECD device doped with AC/IS-Eu shows good cycling stability with reproducible bleaching/coloring over 50 chronoamperometry cycles, high coloration efficiency (CE) values CEin/CEout in the visible (−89/+98 cm2 C−1), and near-infrared (−126/138 cm2 C−1) spectral regions, and outstanding memory effect. Graphical Abstract

Solar spectral management in space using lanthanide-based downshifting layers

Photovoltaic (PV) cells are still the most used energy generation devices for aerospace applications. Although multijunction solar cells represent the standard commercial technology for powering spacecraft, spacecraft companies are still using Si-based PV cells to decrease the cost of satellites at the expense of efficiency and energy generation losses. One of the limitations on solar energy conversion is the mismatch between the solar spectrum and the absorption of the PV technology in use. Thus, strategies to overcome this have been proposed, namely the use of luminescent downshifting layers (DSLs) which are very promising to shape the incident sunlight. In this sense, downshifting materials with absorption in the UV/blue spectral region have been privileged considering the solar spectrum in space environments (AM0 solar spectrum), in which the UV component is larger than that on Earth surface (AM1.5 solar spectrum). Here, we propose the use of Eu3+-doped di-ureasil organic-inorganic hybrid materials as DSLs to be used on large area Si-based PV cells (∼0.1 m2) for space applications. Electrical measurements on the PV cell, done before and after the deposition of the DSLs, confirm the positive effect of the coatings on the device performance, with a relative increase on the generated electrical power of ∼2.6 %. Here, we report, for the first time, a DSL specifically designed for space applications and with the largest active area reported so far.

Improving efficiency of silicon solar cells by integrating SiO2-coated lead-free Cs3Bi2Br9 perovskites quantum dots as luminescence down-shifting layer

Lead-based perovskite quantum dots (QDs) have promising applications in optoelectronic devices, but commercial applications are limited by the potential toxicity and poor stability of lead. Meanwhile, there are lattice, polarity, and thermal expansion coefficient mismatches in integrating semiconductor materials onto the surface of photoelectronic circuit devices, resulting in high-density defects limiting the reliability of photoelectronic devices. Therefore, there is a need to investigate perovskite alternatives that are non-toxic, stable, and can be effectively coupled to silicon photonic circuits. In this paper, lead-free perovskite Cs3Bi2Br9/SiO2 QDs were synthesized. The emission wavelength falls within the 400–560 nm range, exhibiting vibrant blue photoluminescence and demonstrating exceptional air stability for a duration exceeding 60 days. Optical tests and density-functional theory (DFT) calculations show that the silica shell layer effectively binds the electron and hole wave functions, prevents photon-generated carriers from escaping, reduces surface defects, and improves the carrier recombination probability. Meanwhile, using Cs3Bi2Br9/SiO2 QDs as a luminescent down-shifting (LDS) layer in combination with a conventional silicon solar cell, the photovoltaic conversion power was increased by 1.82%. Hence, the core-shell structure is designed by the green environmental protection method to control the improvement of the PL characteristics of QDs, which opens a window for the synthesis of new barrier materials in ethanol and water systems, making the Cs3Bi2Br9/SiO2 QDs have great potential for the application of novel optoelectronic devices in the future.

AgIn5S8/ZnS Quantum Dots for Luminescent Down-Shifting and Antireflective Layer in Enhancing Photovoltaic Performance.

Colloidal AgIn5S8/ZnS quantum dots (QDs) have recently emerged as a promising, efficient, nontoxic, down-shifting material in optoelectronic devices. These QDs exhibit a high photoluminescent quantum yield and offer a range of potential applications, specifically in the field of photovoltaics (PVs) for light management. In this work, we report an eco-friendly method to synthesize AgIn5S8/ZnS QDs and deposit them on commercial silicon solar cells (with an active area of 7.5 cm2), with which the short-circuit current (JSC) enhanced by 1.44% and hence the power conversion efficiency by 2.51%. The enhancements in PV performance are mainly attributable to the improved external quantum efficiency in the ultraviolet region and reduced surface reflectance in the ultraviolet and near-infrared regions. We study the effect of QD concentration on the bifunctions of downshifting and antireflection. The optimal 15 mg/mL QDs blade-coated onto the Si solar cells realize maximum current generation as the reflectance loss in the visible wavelength is compensated by the minimized reflection in the near-infrared region.

The Role of Solar Spectral Beam Splitters in Enhancing the Solar-Energy Conversion of Existing PV and PVT Technologies

The use of photovoltaics (PVs) and/or photo-thermal (PTs) as primary solar-energy solutions is limited by the low solar conversion of PVs due to the spectral mismatch between the incident radiation and/or the PV material. The PTs are curtailed by the limited absorbance and the low thermal conductivity of the working fluid. A possible solution is the use of luminophores able to perform luminescent down-shifting (LDS) conversion and to incorporate them in liquid or solid layers, which act as spectral beam splitters (SBSs). Dispersed in solid polymer layers, luminophores lead to luminescent solar concentrators (LSC). When dispersed in liquid and placed in front of PVs, luminophores act as working fluids and as SBS, leading to hybrid photovoltaic–photo-thermal (PVT) systems. Here, the SBS filters for PV and PVT systems are reviewed. The contribution of luminophores to electrical and thermal energy production is discussed from theoretical, experimental, and economical perspectives. Recent SBS architectural concepts which combine different optical elements are also considered. These architectures can harness the advantageous properties of LSCs, spectral modulators, and hybridisation in a single structure. By combining these different light-management strategies inside of a single structure, an improvement in the electrical and/or thermal energy production can be achieved.

Efficiency enhancement of solar cell by using methylammonium lead tribromide/polymethyl methacrylate hybrid film as luminescent down shifting layer

Luminescent down-shifting (LDS) layer was introduced to tackle the issue of poor short-wavelength response of solar cell. Besides LDS effect, coating a LDS layer on the surface of a solar cell leads to a change in surface reflectance. LDS and antireflection (AR) effect are coupled and usually reported as a single effect. For those solar cell with optimized AR, it is difficult to enhance power conversion efficiency (PCE) with the LDS layer due to the variation of reflectance. In this work, we report an obvious PCE enhancement of two mainstream commercial silicon (Si) solar cells with the optimized AR by using methylammonium lead tribromide (MAPbBr3)/polymethyl methacrylate (PMMA) hybrid film as a LDS layer. The used MAPbBr3/PMMA nanoplatelets solutions for LDS layer have an absolute photoluminescent quantum yield of ∼85 % (excited by 350 nm) in air atmosphere for more than 30 days, laying a foundation for the realization of effective LDS effect. Theoretical analysis has separated the AR and LDS effect. It has demonstrated that AR effect has a positive influence on LDS effect, and PMMA plays the key role in the improvement of AR. Experimental studies further elucidated the LDS and AR effect provided by MAPbBr3/PMMA hybrid film. Thanks to this combined effect, the application of MAPbBr3/PMMA hybrid film as a LDS layer on Si heterojunction solar cell yields a PCE gain of 0.3 % absolute and that on passivated emitter and rear cell produces an absolute PCE enhancement of about 0.7 %.

Aesthetic and efficient perovskite/Si tandem solar cells using luminescent down‐shifting textured anti‐reflection films

AbstractPerovskite‐based tandem cells are emerging as new photovoltaic (PV) cells with a high efficiency that exceeds the efficiency limit of single‐junction cells. Building‐integrated PVs that require high efficiency are attractive, but aesthetics play key roles in these urban applications. One of the most challenging problems with respect to aesthetic PV cells is the efficiency loss due to color tuning. Here, we demonstrate for the first time lossless full‐color tunable PV cells based on the use of textured luminescent down‐shifting (LDS) films with LDS dyes with ultraviolet‐selective absorption. The LDS anti‐reflection (AR) films improve the perovskite/Si tandem cell efficiency by reducing the loss of parasitic UV absorption of the layers above the perovskite film due to LDS effect and the loss due to cell reflection due to the textured surface. Therefore, color tuning with LDS AR films can be used to produce highly aesthetic and efficient PV cells for urban applications.image

Continuously in-situ manufacture of perovskite quantum dots/POE encapsulation adhesive film for silicon solar cell enhancement application

Converting the UV-blue irradiation into longer wavelength can efficiently ameliorate the insufficient solar spectral response and enhance the power conversion efficiency (PCE) of silicon solar cells, whereas there is still no appropriate strategy to make the corresponding luminescence downshifting materials compatible with commercial silicon photovoltaic modules practically. Herein, we first demonstrate an in-situ fabricated CsPbBr3 PQDs/POE encapsulation adhesive film, which can simultaneously achieve continuously large-scale manufacture through melt extrusion and possess well compatibility with the encapsulation technique of silicon photovoltaic modules. According to the separate granulation preparation and technical optimization, the composited adhesive film exhibits an intensive PL emission at 515 nm with a full width at a half-maximum of 20 nm and an ultra high PLQY of 98.2%. Moreover, less than 5% PL intensity decline even after keeping in 50 °C/90 RH aging condition for >2400 h proves its excellent working stability and barrier property. By means of hot pressing operation, the silicon solar cells encapsulated with CsPbBr3 PQDs/POE adhesive film harvest an absolute PCE enhancement of 0.68%. This work provides a way of great potential towards further improving the silicon photovoltaic industry and corresponding optoelectronic applications.

Cesium Copper Halide Perovskite Nanocrystal-Based Photon-Managing Devices for Enhanced Ultraviolet Photon Harvesting.

Space-based solar power harvesting systems with high levels of specific power (the power produced per mass of the mounted photovoltaic cell) are highly desired. In this study, we synthesized high quality lead-free Cs3Cu2Cl5 perovskite nanodisks with efficient ultraviolet (UV) photon absorption, high photoluminescence quantum yields, and a large Stokes shift, which are suitable to serve as photon energy downshifting emitters in the applications of photon-managing devices especially for space solar power harvesting. To demonstrate this possibility, we have fabricated two types of photon-managing devices, i.e., luminescent solar concentrators (LSCs) and luminescent downshifting (LDS) layers. Both experimental results and simulation analyses show that the fabricated LSC and LDS devices exhibit high visible light transmission, low photon scattering and reabsorption energy loss, high UV photon harvesting, and energy conversion after integrating with silicon-based photovoltaic cells. Our research presents a new avenue for utilizing lead-free perovskite nanomaterials in space applications.

In Situ Generating YVO4:Eu3+,Bi3+ Downshifting Phosphors in SiO2 Antireflection Coating for Efficiency Enhancement and Ultraviolet Stability of Silicon Solar Cells

Herein, a solid strategy to prepare bifunctional SiO2 coatings (BSCs) with both antireflection and luminescence downshifting properties by in situ generating YVO4:Eu3+,Bi3+ phosphors in SiO2 antireflection coatings (ARCs) is reported. Namely, a self‐prepared precursor solution of the downshifting phosphors is added to a mixture of commercial SiO2 sol solution and ethanol to uniformly coat the surface of quartz glass; therefore, a novel composite porous SiO2 coating containing in situ generated YVO4:Eu3+,Bi3+ phosphors (labeled SiO2@YVO4:Eu3+,Bi3+ coating) is formed on the glass surface after annealing. The SiO2@YVO4:Eu3+,Bi3+ BSCs can effectively convert ultraviolet (UV) region photons to visible photons that are well absorbed by silicon solar cells and have better transmittance than pure SiO2 ARC. As proof‐of‐concept applications, the as‐prepared optimal SiO2@YVO4:Eu3+,Bi3+ coating can effectively improve the photoelectric conversion efficiency (PCE) of tunnel oxide passivated contact solar cells by 0.18%abs and decrease the UV‐induced degradation value of the PCE of silicon heterojunction solar cells by 0.62%abs compared to the pure SiO2 ARC. The results demonstrate that in situ generating luminescence downshifting phosphors in the SiO2 ARC of photovoltaic glass is a promising way to improve the PCE and UV stability of silicon solar cells.

Intrinsic characteristics of Si solar cells coated with thick luminescence down-shifting sol–gel glass films

We investigate the effects of several-hundred-micron thick luminescence down-shifting (LDS) films composed of sol–gel glass with Zn-based nanoparticles (NPs) dispersed on the characteristics of Si solar cells. Their internal quantum efficiencies (IQEs) are successfully measured by separating the contributions of downshifted photons in measuring reflectance for 300–400 nm, wavelengths of incident photons absorbed by the NPs. We find that IQEs for this wavelength range are more enhanced by employing thicker LDS films, i.e. LDS films with higher optical densities. We also discuss the relationship between the number density of NPs in LDS films, their optical properties, and the IQEs of cells. We observe a discrepancy between the measured and calculated IQEs and note that this is the result of downshifted photons escaping across the sides of the LDS films.

Improving the UV-light stability of silicon heterojunction solar cells through plasmon-enhanced luminescence downshifting of YVO4:Eu3+,Bi3+ nanophosphors decorated with Ag nanoparticles

The ultraviolet (UV) light stability of silicon heterojunction (SHJ) solar cells should be addressed before large-scale production and applications. Introducing downshifting (DS) nanophosphors on top of solar cells that can convert UV light to visible light may reduce UV-induced degradation (UVID) without sacrificing the power conversion efficiency (PCE). Herein, a novel composite DS nanomaterial composed of YVO4:Eu3+,Bi3+ nanoparticles (NPs) and Ag NPs was synthesized and introduced onto the incident light side of industrial SHJ solar cells to achieve UV shielding. The YVO4:Eu3+,Bi3+ NPs and Ag NPs were synthesized via a sol–gel method and a wet chemical reduction method, respectively. Then, a composite structure of the YVO4:Eu3+,Bi3+ NPs decorated with Ag NPs was synthesized by an ultrasonic method. The emission intensities of the YVO4:Eu3+,Bi3+ nanophosphors were significantly enhanced upon decoration with an appropriate amount of ∼20 nm Ag NPs due to the localized surface plasmon resonance (LSPR) effect. Upon the introduction of LSPR-enhanced downshifting, the SHJ solar cells exhibited an ∼0.54% relative decrease in PCE degradation under UV irradiation with a cumulative dose of 45 kW h compared to their counterparts, suggesting excellent potential for application in UV-light stability enhancement of solar cells or modules.

Synthesis, photophysical and electrochemical properties of π-conjugated pyrene based down-shifting molecules with fluorinated aryl groups

Pyrene molecule, with excellent photophysical properties (strong absorption cross section, excellent emission properties and a long-excited state lifetime), excellent thermal and photochemical stability, has been widely used as a building block for the synthesis of pyrene-based fluorophores for optoelectronic applications. In this work, we report the synthesis of two series of pyrene–π–A compounds, series I (3–6) and II (10–13), in which nitro, cyano, cyanoacrylonitrile and cyanoacrylic acid as electron acceptor groups are connected to the pyrene core via aryl or fluoroaryl π-conjugating bridges. The incorporation of fluorine atom on the π-extension bridge cause a slightly red-shift at emission wavelength (λem) in solution and polymethylmethacrylate (PMMA) films and increase the Stokes shift due to greater stabilization of molecular orbitals in the excited state, especially for series I. Solvatochromic measurements and theoretical computational studies suggest a higher intramolecular charge transfer in the excited state for series II when compared to series I due to their stronger electron acceptor moieties. All pyrene derivatives are stable and exhibited initial mass loss at temperature above 200 °C. The good photophysical and thermal properties of the synthesized pyrene derivatives, associated with high molar absorption coefficients in the UV spectrum and good fluorescence emission in the range of 430–480 nm (series I) and 505–567 nm (series II) in PMMA films, make them possible candidates for organic light-emitting diode (OLED) and luminescent down-shifting (LDS) layers for stable perovskite solar cells, respectively.