Full-spectrum Light Research Articles

Tuning luminescence of Ba3Si6O12N2:Eu2+ phosphor for full-spectrum warm white LED lighting

• A cyan emission was achieved via the replacement of Si-N with Al-O in Ba 3 Si 6 O 12 N 2 :0.05Eu 2+ . • The emission peak could be shifted from 512 nm to 495 nm. • The emission intensity of the optimal cyan phosphor is 36% higher than Ba 3 Si 6 O 12 N 2 :0.05Eu 2+ . • The CCT of wLED decreases from 4407 K to 4038 K and the Ra increase from 85.8 to 90.8. Developing cyan phosphors excited by near ultraviolet (n-UV) or blue LED chips is extremely significant for making up for the cyan cavity of the existing white light emitting diodes (wLEDs). In this research, a cyan emission was successfully achieved via the replacement of Si-N with Al-O in Ba 2.85 Si 6 O 12 N 2 :0.15Eu 2+ green phosphor. The emission peak could be shifted from 512 nm to 495 nm. The mechanism of spectral blue shift can be interpreted by the decrease of the crystal field splitting strength, which is induced by the square of the bond length and the decrease of centroid shift of 5d level, which is induced by the spectroscopic polarizability and 6th power of the bond length. The optimal cyan Ba 2.85 Si 5.65 Al 0.35 O 12.35 N 1.65 :0.15Eu 2+ phosphor possess a broad excitation and emission band at the same time, whose emission intensity is 36% higher than that of Ba 2.85 Si 6 O 12 N 2 :0.15Eu 2+ . The CCT of the wLED with Ba 2.85 Si 5.65 Al 0.35 O 12.35 N 1.65 :0.15Eu 2+ phosphor realizes from 4407 K to 4038 K and the Ra values achieve from 85.8 to 90.8. The results indicate that Ba 2.85 Si 6- y Al y O 12+ y N 2- y :0.15Eu 2+ phosphor can serve as a cyan component for application in full-spectrum warm white lighting.

The effects of bright white light therapy on obese frailty in older men with prostate cancer on hormonal therapy: A pilot randomized control trial.

75 Background: Exposure to bright white light (BWL) has been shown to improve outcomes including fatigue, depression, and sleep disturbances among the general older population but the benefit has not been demonstrated as yet in prostate cancer. Older men with prostate cancer on androgen deprivation therapy (ADT) are at risk for obese frailty (components: fatigue, weakness, poor mood, slowness and obesity). In this pilot study, we aimed to determine if BWL, compared to dim white wight (DWL), reduces obese frailty in older prostate cancer patients starting anti-androgens. Methods: Men age ≥ 65 with prostate cancer initiating ADT were randomly assigned to either the BWL (exposure to full spectrum light, 500-1500 lux) or DWL cohort (exposure to low dose white light (<50 lux)) and were blinded to assignment. Men received daily 30-minute morning light session from special glasses (Luminette) for 3 months. Participants were assessed at the beginning of treatment and 3 months later with the Short Physical Performance Battery (SPPB) - including timed 4m walk, tandem balance, and timed chair stands (range: 0 to 12) - energy levels (self-reported 5-point Likert scale), waist circumference (measured via tape (mm)), and muscle strength (handgrip: assessed via dynamometer (kg)). Pre-post outcomes (means differences) were evaluated using paired t-tests with a p-value of 0.05 considered significant. Results: 18 patients (9 per cohort) were recruited. Patients in the BWL arm showed a statistically significant improvement in muscle strength (BWL p=0.012 versus in DWL p=0.22). Compared with DWL, BWL arm showed no decline in energy levels, (BWL p=0.28 vs. DWL p=0.035) nor gain in waist circumference (BWL p=0.51, DWL p=0.046). There were no statistically significant differences in either arm on the SPPB (BWL p=0.44, and in DWL p=0.09). Conclusions: BWL may offset negative effects of ADT for older men with prostate cancer, through improved muscle strength, maintained energy levels, and no waist circumference gain. While a small pilot study, the intervention warrants further research in a larger sample.

Efficient solar-light conversion for optimizing the catalytic ozonation of gaseous toluene with PdOx-LaFeO3

Solar-energy conversion is a promising strategy to enhance efficiency and save energy for pollutant elimination. In this study, we combined LaFeO3 and PdOx to simultaneously convert the energy from ultraviolet (UV), visible, and infrared (IR) light and thus enhance the catalytic ozonation of toluene. The contribution of photothermal and photoelectric effect for the prepared samples was evaluated by temperature and light-controlled experiments. Results revealed that the removal and mineralization efficiencies of toluene for 10%PdOx-LaFeO3 reached 52.9% and 40.2%, respectively, under full-spectrum illumination. The synergistic factor of full-spectrum light and ozone for 10%PdOx-LaFeO3 was 3.19 times higher than that for LaFeO3. The incident-light and absorbed-light photothermal-conversion efficiencies of full-spectrum for 10%PdOx-LaFeO3 were 2.0 and 1.7 times higher than that for LaFeO3, respectively. PdOx loading also significantly promoted the separation efficiency of photogenerated charge carriers and expanded the valid spectrum of photoelectric effect from the ultraviolet to visible regions.

Full Spectrum Lighting Induces Behavioral Changes and Increases Cortisol Immunoreactivity in Captive Arachnids

ABSTRACT The use of full spectrum illumination, including ultraviolet (UV), during captive husbandry of arachnids is common practice. The effect of this on captive arachnids has not been previously investigated. Comparison of key behavioral changes and hemolymph cortisol immunoreactivity was undertaken with and without full spectrum lighting. King baboon spiders, Pelinobius muticus and Indian giant scorpions, Heterometrus swammerdami were selected for the study. Both organisms spent all their time hidden when exposed to full spectrum light compared to low-level ambient light except for one instance. There was no significant difference in burrowing and webbing in P. muticus when exposed to full spectrum lighting. There was a decrease in the number of behaviors or postures expressed in full spectrum lighting compared to ambient light for both species. Cortisol immunoactivity of both species were significantly elevated after exposure to full spectrum lighting. This study provides the first evidence of detectable cortisol immunoactivity in arachnid hemolymph. These levels changed in response to full spectrum illumination and were linked to behavioral changes. This suggests that a common husbandry practice may be detrimental to arachnids.

BiVO4 ternary photocatalyst co-modified with N-doped graphene nanodots and Ag nanoparticles for improved photocatalytic oxidation: A significant enhancement in photoinduced carrier separation and broad-spectrum light absorption

The efficient removal of antibiotics in water is essential to protect aquatic environment as antibiotics are some of the most hazardous pollutants in water. Herein, we report the synthesis of a novel N-GNDs/Ag/BiVO4 ternary photocatalyst consisting of BiVO4 coupled with Ag nanoparticles (Ag-NPs) and nitrogen-doped graphene nanodots (N-GNDs) to degrade and mineralize tetracycline hydrochloride (TC•HCl) in water. The ternary photocatalyst shows higher photocatalytic degradation of TC•HCl under full spectrum light than pure BiVO4. Based on the morphology, crystalline structure, physicochemical properties, and photoelectrochemical behavior of the ternary photocatalyst, the enhanced photocatalytic performance is attributed to the upconversion effect of N-GNDs and the localized surface plasmon resonance (LSPR) effect of Ag-NPs. Thus, the synergetic effects expand the absorption range of light and significantly promotes the separation of photoexcited carriers. Further, a possible photocatalytic reaction mechanism of TC•HCl degradation over N-GNDs/Ag/BiVO4 is discussed via through investigation of the charge carrier migration, active species, and intermediates in the degradation processes.

The impact of Au nanoparticles and lanthanide-doped NaYF4 on the photocatalytic activity of titania photocatalyst

Composite systems were prepared by doping NaYF4 (NYF) with lanthanide cations (Yb3+, Er3+, Tm3+), TiO2, and gold nanoparticles to exploit the light conversion properties of NYF and its possible impact on the photocatalytic activity of the composites. The composites were synthesized via solvothermal crystallization and the obtained structures were anatase TiO2, hexagonal NYF, and gold nanoparticles of 5–7 nm. The presence of NYF enhanced the photoactivity of TiO2 towards Rhodamine B degradation under UV irradiation, while it decreased its performance under visible light. The presence of Au was beneficial when visible light was applied for the degradation experiments. The reason behind the enhanced activity was the fluorescence of NYF at 400 nm that was the most intense for the composites that did not contain gold. The NYF-based samples also showed signs of up-conversion when 900 nm was the excitation light source, highlighting the potential of this material for photocatalytic applications that utilize the full (UV–IR) light spectrum.

Floral Induction in the Short-Day Plant Chrysanthemum Under Blue and Red Extended Long-Days.

Shorter photoperiod and lower daily light integral (DLI) limit the winter greenhouse production. Extending the photoperiod by supplemental light increases biomass production but inhibits flowering in short-day plants such as Chrysanthemum morifolium. Previously, we reported that flowering in growth-chamber grown chrysanthemum with red (R) and blue (B) LED-light could also be induced in long photoperiods by applying only blue light during the last 4h of 15h long-days. This study investigates the possibility to induce flowering by extending short-days in greenhouses with 4h of blue light. Furthermore, flower induction after 4h of red light extension was tested after short-days RB-LED light in a growth-chamber and after natural solar light in a greenhouse. Plants were grown at 11h of sole source RB light (60:40) in a growth-chamber or solar light in the greenhouse (short-days). Additionally, plants were grown under long-days, which either consisted of short-days as described above extended with 4h of B or R light to long-days or of 15h continuous RB light or natural solar light. Flower initiation and normal capitulum development occurred in the blue-extended long-days in the growth-chamber after 11h of sole source RB, similarly as in short-days. However, when the blue extension was applied after 11h of full-spectrum solar light in a greenhouse, no flower initiation occurred. With red-extended long-days after 11h RB (growth-chamber) flower initiation occurred, but capitulum development was hindered. No flower initiation occurred in red-extended long-days in the greenhouse. These results indicate that multiple components of the daylight spectrum influence different phases in photoperiodic flowering in chrysanthemum in a time-dependent manner. This research shows that smart use of LED-light can open avenues for a more efficient year-round cultivation of chrysanthemum by circumventing the short-day requirement for flowering when applied in emerging vertical farm or plant factories that operate without natural solar light. In current year-round greenhouses’ production, however, extension of the natural solar light during the first 11 h of the photoperiod with either red or blue sole LED light, did inhibit flowering.

Uncovering the origin of full-spectrum visible-light-responsive polypyrrole supramolecular photocatalysts

Environmentally friendly polypyrrole (PPy) catalysts with conjugated nanostructures for superior photophysical and photoelectric applications are developed. The high coplanar structure via α-α connection is benefit for the transferring of photo-induced electron and improving the life of the light generated carrier. Importantly, the energy level structure of conjugated polymers was obtained via theoretical calculation and the photocatalytic mechanism of PPy photocatalyst was illuminated in detail. O2− are the main radical responsible for the degradation of MO. Moreover, conjugated PPy photocatalysts are stable with cycling. Compared to P25 and g-C3N4, PPy showed excellent photocatalytic performance for degradation of organic pollutants in full spectrum and visible light, the reaction rate constants of PPy are 4.27 and 5.31 times as much as the P25, respectively. Furthermore, PPy also exhibited effective photocatalytic performance towards different organic pollutants. These results obviously open interesting perspectives of using conjugated polymer and provide theoretical guidance for designing new organic photocatalysts to solve the energy and environment issues.

Ultrathin zinc selenide nanosheet-based intercalation hybrid coupled with CdSe quantum dots showing enhanced photocatalytic CO2 reduction

Fabrication of well-designed heterojunctions is an extraordinarily attractive pathway for boosting the photocatalytic activity toward CO2 photoreduction. Herein, a novel kind of nanosheet-based intercalation hybrid coupled with CdSe quantum dots (QDs) was successfully fabricated by a facile solvothermal method and served as photocatalyst for full-spectrum-light-driven CO2 reduction. Ultra-small CdSe QDs were rationally in-situ introduced and coupled with lamellar ZnSe-intercalation hybrid nanosheet, resulting in the formation of CdSe QDs/ZnSe hybrid heterojunction. Significantly, the concentration of Cd2+ could change directly the crystallinity and micromorphology of ZnSe intercalation hybrid, which in turn would impact on the photocatalysis activity. The optimized CdSe QDs/ZnSe hybrid-5 composite demonstrated a considerable CO yield rate of the 25.6 μmol g−1 h−1 without any additional cocatalysts or sacrificial agents assisting, making it one of the best reported performance toward CO2 photoreduction under full-spectrum light. The elevated CO2 photoreduction activity could be attributed to the special surface heterojunction, leading to improving the ability of light absorption and promoting the separation/transfer of photogenerated carriers. This present study developed a new strategy for designing inorganic-organic heterojunctions with enhanced photocatalyst for CO2 photoreduction and provided an available way to simultaneously mitigate the greenhouse effect and alleviate energy shortage pressure.

Photocatalytic, thermometric and internal heating multifunctional properties of Er3+/Yb3+-codoped MoO3 upconverting microparticles

To solve the existing challenges of luminescent materials for multifunctional applications, we developed Er3+/Yb3+-codoped MoO3 upconvering microparticles as promising platforms towards thermometry, optical heater and photocatalysis. At 980 nm light excitation, bright upconverison (UC) emissions are generated and the emission intensities are dependent on the doping content. The optimal doping content is 3 mol% and the UC emission mechanism is contributed by a tow-photon absorption process. Through analyzing the temperature-dependent UC emission intensities of thermally coupled levels of Er3+ ions, the thermometric properties of the final products are studied. The maximum absolute and relative sensitivities of the designed microparticles are 0.0093 K-1 and 2.9% K−1, respectively, which are insensitive to the dopant content. Furthermore, the laser pump power triggered internal heating properties of the developed samples are also investigated, in which the temperature of the samples is elevated from 318.7 to 587.6 K when the laser pump power is adjusted from 59 to 359 mW. Additionally, the designed microparticles can degrade pollutant efficiently upon full spectrum light irradiation. Compared with the MoO3, these compounds doped with Er3+ and Yb3+ ions show superior photocatalytic activities, in which the h+, ▪ and ·OH species can contribute to the involved photocatalytic mechanism. This work initiates a new insight to search for rare-earth ions doped upconverting materials for versatile applications.

Full-visible-spectrum lighting realized by a novel Eu2+-doped nitride-based cyan-emitting phosphor.

Cyan phosphors have attracted considerable attention in recent years as an indispensable component for realizing full-spectrum lighting. In this study, a novel nitride-based cyan-emitting phosphor Ca2BN2Cl:Eu2+ was successfully prepared. Its crystal structure refined by the Rietveld refinement reveals that Ca2BN2Cl is formed by a tight host lattice and the edge-sharing Ca(N,Cl)4 tetrahedrons along with multiple crystallographic Ca sites for Eu2+ ions to occupy, which corresponds to its broad emission band. Under the near ultraviolet (NUV) light excitation, Ca2BN2Cl:Eu2+ emits a broad-band cyan light and its full width at half-maximum (FWHM) can reach 121 nm, which effectively compensates the "cyan cavity". The time-resolved photoluminescence (TRPL) spectra of Ca2BN2Cl:Eu2+ were investigated to expose the energy transfer between the multiple luminescent centers. Furthermore, the temperature-dependent spectra of Ca2BN2Cl:Eu2+ were measured to evaluate its thermal stability. All of the discussion and results reveal that Ca2BN2Cl:Eu2+ is a promising cyan phosphor for use in white light-emitting diodes to realize full-spectrum lighting.

S-scheme bismuth vanadate and carbon nitride integrating with dual-functional bismuth nanoparticles toward co-efficiently removal formaldehyde under full spectrum light

It is crucial to develop more effective photocatalysts in the field of clean environment. In response, the S-scheme BiVO4/g-C3N4 heterojunction modified by in situ reduced non-noble metal Bi nanoparticles was used to synergistically degrade formaldehyde under full spectral irradiation. The results, that investigated by careful characterizations and density functional theory (DFT) calculations, proved that BiVO4/g-C3N4 form an S-scheme heterojunction, which can effectively improve the separation efficiency of photogenic carriers and maintain the original strong redox capability of semiconductor materials. The SPR effect of Bi elemental substance enhanced the optical response and provided more oxidative species. Thus, the photocatalytic activity of BiVO4/Bi/g-C3N4 was significantly improved through their joint efforts, that the degradation efficiency of HCHO (800 ppm) for 6 h is 96.39% under 300 W Xenon lamp without filter with the pseudo-second-order rate constant of 4.16 ppm−1·h−1 and CO2 selectivity of 98.41%. Surprisingly, the degradation efficiency also reached to 49.35% and 32.23% under visible and near-infrared light irradiation, respectively. Moreover, we also tested its photocatalytic decomposition effect on formaldehyde in coatings, indicating that it has a broad prospect in future coatings applications. This study may provide an expected photocatalyst, an efficient non-noble metal modified S-scheme heterojunction, to degrade volatile organic gases under a broad spectrum light.

Magnetically separable highly efficient full-spectrum light-driven WO2.72/Fe3O4 nanocomposites for photocatalytic reduction of carcinogenic chromium (VI) and organic dye degradation

In this study, magnetically separable, highly efficient full-spectrum light active WO2.72/Fe3O4 nanocomposites were synthesized by a solvothermal method and well characterized. The photocatalytic property of WO2.72/Fe3O4 nanocomposite toward photodegradation of methylene blue (MB), methyl orange (MO), and rhodamine B (Rh B) dyes under solar and photoreduction of Cr(VI) under ultraviolet (UV), visible, and solar light were studied. The WO2.72/Fe3O4 nanocomposite exhibited excellent photocatalytic activity for the photodegradation of MO, MB, and Rh B dyes under solar light and photoreduction of Cr(VI) under visible, UV, and solar light. The WO-FO-0.5 nanocomposite exhibited 2.9, 1.6, and 2.0 times the photocatalytic activity of Fe3O4 for Cr(VI) photoreduction under solar, visible, and UV and 20, 29.2, and 16 times that of Fe3O4, for Rh B, MB, and MO under solar light. It doesn't show only universal applicability for photocatalysis of different organic and inorganic pollutants but, also outstanding stability and easy separability. The nanocomposite also exhibited higher photocatalytic activity than that reported for photoreduction Cr(VI) under solar light. It is also convenient for large-scale applications due to its low cost, eco-friendliness, and easy preparation. Therefore, it is a promising candidate for environmental remediation under full-spectrum solar light.

Full Spectrum Phosphors for White LEDs and Virtual Windows for Light and Health Applications

Light and health is a topic of significant importance and requires fundamental studies of human interactions with light. This talk will present a review of some of the on-going studies on light and health by holistically exposing the humans to the outdoor conditions, while they are confined in indoor spaces. The designs of a new lighting-display fusion system along with examples of emerging commercial products will be discussed. Full spectrum lighting is a critical component of such systems. Results of phosphor blends based on well known thiogallates and sulfide phosphors for designing full spectrum lighting that could replicate sunlight quality will be presented. The synchronous modulation of phosphor based full spectrum light sources with electronic display playing real time outdoor videos creates a new tool for systematically studying the cognitive psycho-physiological health of human beings under different environmental conditions.

One step synthesis of self-doped F–Ta2O5 nanoshuttles photocatalyst and enhanced photocatalytic hydrogen evolution

Tantalic oxide (Ta2O5), as an excellent transition metal oxide photocatalyst, has been extensively studied on fluorination or self-doped for hydrogen production, while there is little research to combine the two modifications. In this work, surface fluorination self-doped Ta2O5 nanoshuttles (FTNSs) photocatalyst is synthesized successfully by a modified one-step hydrothermal method. The test results show the presence of surface fluorine ions, Ta4+ and oxygen vacancies in the sample. The FTNSs prepared by hydrothermal method under 180 °C for 24 h exhibits the highest hydrogen evolution rate (HER). The HER is 179.2 and 19.78 μmol h−1 g−1 in the absence of any co-catalyst under full-spectrum and simulated solar light, respectively, which is higher than that of the Ta2O5 nanoshuttles without fluoride and the commercial Ta2O5. The higher HER can attribute to the existence of F, Ta4+ and oxygen vacancies, which enhance the photogenerated carrier mobility and reduce the recombination.

Construction of full spectrum-driven CsxWO3/g-C3N4 heterojunction catalyst for efficient photocatalytic CO2 reduction

Full spectrum-driven CsxWO3/g-C3N4 catalyst was successfully synthesized by the combination of solvothermal and ultrasonication methods and used in CO2 photocatalytic reduction. The experimental results suggested that 20 wt% CsxWO3/g-C3N4 catalyst possessed the best yield of CH4 under NIR and full spectrum light irradiation, which were 1.72 and 6.79 μmol·g−1·h−1, respectively. This outstanding photocatalytic activity could be attributed to the localized surface plasmonic resonance effect and the formation of heterojunction structure, which led to the improved charge separation efficiency, good light-harvesting ability and broadened light response.

Improved performance of quantum dot-sensitized solar cells by full-spectrum utilization

One of important factors for improving the power conversion efficiency (PCE) of quantum dot-sensitized solar cells is to enhance the utilization of sunlight. Herein, we modified the wavelength range of incident sunlight from the counter electrode (CE) side to investigate the photoelectric performance of solar cells. The effect of illuminating CuS and Cu2S CE with different light ranges (including non-illumination, UV–visible light, NIR light and full-spectrum light) on cell performance was investigated. It has been shown that illuminating from both sides of cell induce substantial increase in PCE, and a 42.8% enhancement in PCE compared with that irradiating from the photoanode side has been achieved with a champion PCE of 5.6% (Voc = 0.6 V, Jsc = 21.7 mA cm−2) based on CuS CE. This strategy focuses on the neglected problem of light utilization of the CE, and provides a direction for realizing full-spectrum absorption of liquid-junction solar cells.

Photocatalytic Properties of Graphene/Gold and Graphene Oxide/Gold Nanocomposites Synthesized by Pulsed Laser Induced Photolysis.

Graphene (Gr)/gold (Au) and graphene-oxide (GO)/Au nanocomposites (NCPs) were synthesized by performing pulsed-laser-induced photolysis (PLIP) on hydrogen peroxide and chloroauric acid (HAuCl4) that coexisted with Gr or GO in an aqueous solution. A 3-month-long aqueous solution stability was observed in the NCPs synthesized without using surfactants and additional processing. The synthesized NCPs were characterized using absorption spectroscopy, transmission electron microscopy, Raman spectroscopy, energy dispersive spectroscopy, and X-ray diffraction to prove the existence of hybrid Gr/Au or GO/Au NCPs. The synthesized NCPs were further evaluated using the photocatalytic reaction of methylene blue (MB), a synthetic dye, under UV radiation, visible light (central wavelength of 470 nm), and full spectrum of solar light. Both Gr/Au and GO/Au NCPs exhibited photocatalytic degradation of MB under solar light illumination with removal efficiencies of 92.1% and 94.5%, respectively.

In-situ growth of high-density ultrafine Ag3PO4 nanoparticles on 3D TiO2 hierarchical spheres for enhanced photocatalytic degradation of organic pollutants

Silver phosphate (Ag3PO4, APO) has attracted intense attention as a visible-light-driven photocatalyst, but its large-scale application is limited by severe charge recombination and inevitable photo-corrosion. Various rational APO-based heterostructures composed of APO nanoparticles (NPs) and band-matched semiconductor support are designed to address the above issues. Nevertheless, the size, density, stability, and dispersion of APO NPs are critical challenges for the photocatalytic performance of APO-based photocatalysts. Here, three-dimensional (3D) self-assembled TiO2 hierarchical spheres (THS) prepared by a simple one-step hydrothermal method are employed as innovative support, and ultrafine high-density APO NPs with an average size of about 3 nm are successfully deposited and uniformly dispersed throughout THS to form hierarchical THS/APO composites. The novel THS/APO microstructure provides abundant reactive sites for photocatalytic reactions and promotes the photogenerated charge separation and transfer due to the ultrafine size of APO NPs and the TiO2/APO Type-II heterojunction. As a result, the THS/APO composites show significant improvement in photocatalytic activity and stability in methylene blue (MB) degradation. The reaction constant of THS/APO composites far exceeds that of either THS or APO, roughly 16 and 7 times higher than that of THS and APO under full-spectrum light, and 41 and 4 times higher under visible light. Our results strongly suggest new insights into the low-cost, large-scale application of high-efficiency APO-based photocatalyst.

Extreme sensitivity of dye solar cells to UV‐induced degradation

AbstractPresent practice to avoid harmful effects of UV light on dye solar cells (DSC) is to use a UV filter. However, we show here that a standard 400 nm UV cutoff filter offers inadequate protection from UV‐induced degradation. DSCs that were exposed to only visible light by LED lamps maintained 100% of their initial efficiency after 3000 hours of exposure, whereas the efficiency of DSCs subjected to full light spectrum (Xenon arc lamp) with an efficient UV filter dropped down to 10% of their initial performance already after 1500 hours. Optical analysis of the UV filter confirmed that the amount of light transmitted below 400 nm was negligible. These observations indicate that (a) DSCs can be very sensitive to even minor amount of UV and (b) eliminating the effects of UV light on DSC stability cannot easily be avoided by a UV filter on top of the cell. A detailed analysis of the degradation mechanisms revealed that the culprit to loss of performance was accelerated loss of charge carriers in the electrolyte of the DSCs—a typical symptom of UV exposure. These results suggest that commonly used stability tests under LED illumination are insufficient in predicting the lifetime of DSCs in outdoor conditions. Instead, for such purpose, we recommend solar cell stability to be tested with a full light spectrum and with a suitable UV filter.