Down-conversion Research Articles

Luminescent MoS2 quantum dots with reverse saturable absorption prepared by pulsed laser ablation

Effects of quantum confinement, focusing on upconversion and downconversion photoluminescence and reverse saturable absorption, on MoS2 quantum dots produced by nanosecond UV laser ablations is not widely reported. The effect of wavelength and pulse energy of ablating laser on the size, colloidal stability, upconversion and downconversion photoluminescence and non-linear properties of MoS2 quantum dots (QDs) are reported here. MoS2 QDs are grown by pulsed laser ablation (PLA) from bulk MoS2 pellets in deionized (DI) water with UV (355 nm), visible (532 nm) and IR (1064 nm) laser beams from a nanosecond Nd-YAG laser source and ablation is repeated with varying pulse energy. The target MoS2 pellet prepared for ablation was sintered at 800 °C in nitrogen ambience for 8 h. Hexagonal structure of MoS2 pellet is confirmed by XRD and Raman spectroscopy before and after sintering. The exfoliated MoS2 QDs dispersion show appreciable photon upconversion (UPC) and down conversion (DC) photoluminescence (PL). The downconversion PL emission shows multiple peaks. QDs size is found to vary with the wavelength of the ablating laser beam. The mean particle size, measured by dynamic light scattering measurements and TEM analysis, is in the range of 2–30 nm. Absorbance measurement shows high energy peaks around 5.88 eV (211 nm) with shoulder peak at 3.79 eV (327 nm) corresponding to MoS2 QDs. MoS2 QDs dispersion show moderate dispersion stability as per zeta potential analysis. Raman analysis of spin coated few layer MoS2 QDs shows characteristic in-plane (E12g) and out-of-plane (A1g) vibrational modes of MoS2. Nonlinear optical studies of colloidal MoS2 show reverse saturable absorption (RSA) due to two photon absorption (TPA) process.

Hydrothermal synthesis of ScVO4:Ln3+ (Ln = Eu, Dy, Eu/Dy) microcrystals with controllable morphology, energy transfer and multicolor luminescence

ScVO4:Ln3+ (Ln = Eu, Dy, Eu/Dy) were prepared by hydrothermal method without employing any organic additives. X-ray diffraction (XRD), scanning electron microscopy (SEM) and down-conversion (DC) spectra were used to characterize the phase, morphology and luminescence of the obtained samples, respectively. The effect of pH value and reaction time on the morphologies (including dodecahedrons, olive tetrahedrons, rectangular blocks and micrometer rods) and sizes of ScVO4 were studied in detail. Additionally, the possible formation mechanism of ScVO4 dodecahedral was considered as a dissolution recrystallization process. Under UV excitation, the red emission of ScVO4: Eu3+ at 622 nm from the 5D0-7F2 transition and the blue and yellow emissions of ScVO4:Dy3+ microcrystals at 484/579 nm assigned to the 4F9/2 – 6H15/2 and 4F9/2 – 6H13/2 transitions were observed. Multicolor emissions (blue → yellow → white → orange → red) of ScVO4: Eu3+/Dy3+ phosphors can be flexibly adjusted through controlling the ratio of Dy3+ to Eu3+ concentration under optimal excitation of 282 nm. And multicolor luminescence can also be obtained via adjusting the excitation wavelength at a constant doping concentration. The as-synthesized phosphors might be potentially applied in display devices, decorative lights and illuminations.

Tailoring UV-blue sensitization effect in enhancing near infrared emission in X, Yb3+: CaGa2O4 (X = 0, Eu3+, Bi3+, Cr3+) phosphor for solar energy conversion

This work presents a strategy to modify the UV–vis part of solar spectrum into near infrared (NIR) region- an operational region for silicon solar cells. CaGa2O4, a wide band gap material, has been doped with Yb3+ ion and different sensitizers (Bi3+, Eu3+ and Cr3+) in order to probe the NIR emitting properties through downconversion (DC) process. Of these, Cr3+ ion serves the purpose of maximum conversion efficiency in a best way owing to its wide excitation spectrum spanning over the entire UV-blue region. The mechanisms involved in obtained results are supported by the decay curve measurement and energy transfer studies. Further, germainum ion is also doped to get long afterglow Yb3+ ion emission. This doping develops deep-traps that can store excitation energy and transfer it cooperatively via DC to Yb3+ for a longer time. Thus, the material is a promising spectral converter for c-Si solar cells and other photochemical processes.

Impact of firing temperature on multi-wavelength selective Stokes and anti-Stokes luminescent behavior by Gd2O2S:Er,Yb phosphor and its application in solar energy harvesting

Erbium (Er3+)–ytterbium (Yb3+) doped gadolinium oxysulphide (Gd2O2S) phosphor has been developed via a facile method of solid-state flux fusion, and offers two-fold spectrum modification with highly intense Stokes and anti-Stokes shift. The effect of the firing cycle on the photoluminescent response and morphology of Gd2O2S:Er,Yb is scrutinized, wherein the firing temperature was varied (1000 °C–1250 °C), keeping firing time and all other parameters constant. Interestingly, the nanostructures fired below 1150 °C showed nanorods of diameter ~200 nm and length ~1–2 µm, whereas firing at 1150 °C and above rendered nanospheres with small diameter, ~350 nm. Highly bright upconversion (UC) emission was achieved even under an extremely low excitation power density of 800 µW cm−2 from a 980 nm laser, and was comfortably visible to the naked eye. The incident power dependent studies disclosed increase in UC-emission intensity with increasing excitation power and a quasi-linear dependence on excitation power density. Intense characteristic UC-emission of Er3+ excited states at 525 nm, 556 nm and 668 nm were observed, and the green emission band was found to be dominant over the red band in intensity. Concurrently, downconversion (DC) emission at 556 nm and 669 nm was also exhibited under ultraviolet excitation (285 nm and 380 nm), with the red band being more powerful than the green, unlike UC-emission. Firing temperature dependent studies divulged the dependence of luminescence intensity on the firing cycle of the luminophore and formation of the respective luminescent phase. The UC-emission intensity was found to be maximum for samples fired at 1150 °C, whereas samples fired at 1000 °C showed the highest DC-emission intensity. The excitation and emission profile of single Gd2O2S:Er,Yb phosphor lying in the desired spectral region and as a dual spectral converter marks its possible application for enhanced harvesting of sunlight.

Ho3+-Yb3+:YMoO4 core@shell nanoparticles for enhanced visible upconversion and security applications

Ho3+-Yb3+ sensitized YMoO4 core@shell upconversion (UC) nanoparticles (NPs) have been structurally and optically characterized. Bright Field Transmission Electron Microscopy (TEM) imaging and the corresponding Fast Fourier Transform (FFT) pattern has been done to evidence the formation of core@shell nanostructures. Optical properties viz. UV–Vis absorbance spectra, Dynamic Light Scattering (DLS), zeta potential measurement and upconversion (UC)/downconversion (DC) spectra of core and core@shell nanoparticles have been reported. The core@shell NPs exhibits both the colloidal stability and solubility in well suited biological liquids. Due to silica shell across the Ho3+/Yb3+ codoped YMoO4 NPs, the frequency UC emission intensity of all bands have been increased compared to that of core NPs. The colour emitted from the core@shell NPs lies in the green region having colour purity ∼95%. In biocompatible solvents under 980 nm excitation, the reduction in the overheating problem is due to small decrement in the UC emission intensity of core@shell NPs compared to that of the core NPs.

Tb3+/Yb3+ doped aluminosilicate phosphors for near infrared emission and efficient down-conversion

The spectral mismatch between incident solar photons and the bandgap of crystalline silicon in solar cells results in major energy losses. Photons with energies lower than the bandgap are lost due to transparency, while those with energies above the bandgap value will be absorbed, generating electron-hole pairs, but consuming only the energy Eg, with the excess being lost as heat through thermalization. Despite intensive research to obtain efficient down-conversion (DC) materials for frequency shifting layers in c-Si cells, their development so far involves techniques which are not cost effective. Taking this into account, aluminosilicate phosphors co-doped with the Tb3+/Yb3+ ion pair have been synthesized by sol-gel (SG) processing, a low cost technique which allows scalability and is especially useful to obtain films. The molar composition 90 SiO2-10 AlO1.5 was chosen as host to investigate if DC based on the Tb3+/Yb3+ pair leads to efficient quantum cutting in such material. We demonstrate the potential of this approach to obtain near infrared DC emission in aluminosilicate matrix with a conversion efficiency of up to 158%, with potential to improve the performance of low bandgap photovoltaic solar cells.

Intense blue upconversion emission and intrinsic optical bistability in Tm3+/Yb3+/Zn2+ tridoped YVO4 phosphors

Tm3+/Yb3+/Zn2+:yttrium metavanadate (YVO4) phosphors prepared through chemical coprecipitation and the solid state reaction method have been structurally characterized by an x-ray diffraction (XRD) study. Photoluminescence study of the developed phosphors under ultraviolet (UV) and near infrared (NIR) excitation has been performed. The excitation spectrum of the tetragonal zircon type YVO4 phosphors corresponding to the emission at ∼476 nm exhibits a broad excitation peak in the 250–350 nm region, which is due to charge distribution in the group. Under 980 nm CW diode laser excitation, enhancements of about ∼3000 times and ∼40 times have been observed for the blue band in the tridoped Tm3+Yb3+Zn2+:YVO4 phosphors compared to those of the Tm3+:YVO4 singly and Tm3+/Yb3+:YVO4 codoped phosphors, respectively. A downconversion (DC) emission study shows an enhancement of about ∼50 times for the blue band in the tridoped phosphors compared to that of the singly doped phosphors. Optical bistability (OB) behavior of the developed phosphors has been also investigated upon 980 nm excitation. The calculated Commission Internationale de l’Éclairage (CIE) color coordinates lie in the blue region with 96.5% color purity under 980 nm excitation, having a color temperature of ∼3400 K. Our observations show that the developed phosphors may be suitably used in dual mode luminescence spectroscopy, display devices, and UV LED chips.

Integrating Down-Shifting and Down-Conversion into Metal–Organic Frameworks to Enhance the Spectral Conversion for Solar Cells

Luminescent spectral conversion, including down-conversion (DC) and down-shifting (DS) is a potential route to overcome the spectral mismatch between solar photons and the semiconductor energy gap. Here, we introduce metal organic frameworks (MOFs) that integrate DC and DS processes into one system. Three different MOFs (Gd(BTC)(1), Gd(BPT)(2), and Gd(OBT)(3)) were synthesized doped with lanthanide ions couples. The DS–DC synergistic fluorescent processes were observed in all the MOFs. The overall absorption and near-infrared (NIR) emission intensity are dramatically enhanced (by factors of ∼4 800 and 550) due to the DS-sensitized effect for DC. As for DS process, the DC-bridge effect is quantified for the first time by comparing the NIR quantum yield (QYNIR). Benefiting from the bridge effect, QYNIR (5.30%) of Dy0.01Yb0.10-3 is increased around 3 times greater than the system without DC process, and it is close to the highest value reported for the C–H bond containing Yb3+ emitter. Our study demonstrated...

Correlation of crystal structure and optical properties of Ba0.97Nd0.0267Ti(1-x)W x O3 perovskite.

The Ba0.97Nd0.0267Ti(1−x)WxO3 (BNTx) pervoskite with a single phase tetragonal structure was prepared at 900 °C using the Molten salt method. Raman spectra, Fourier transform infrared spectra (FT-IR), absorption spectra (Vis-NIR) and photoluminescence spectra (PL) in the temperature range from 10–300 K were used to investigate the correlations between the crystal structure and the optical properties of BNTx ceramics. Raman analyses and FT-IR indicated that the W6+ ions are incorporated sufficiently into into the BNTx lattice. The optical absorption spectra were recorded in the wavelength range of 400–1000 nm. The optical band gap (Eg) and Urbach energy (Eu) values were calculated from the absorption spectra. The emission spectra exhibited three prominent peaks located at 880, 1058 and 1340 nm corresponding to the 4F3/2 → 4I9/2,11/2,13/2 transition levels, respectively. They also showed a decrease in the intensity of emission spectra following the addition of W6+ ions. This decrease is due to the slight changes in the crystal environment around Nd3+ and the non-radiative energy transfer. According to the PL measurements, the study of power-excitation density confirmed that two photons at low energy are required to create the down-conversion (DC) emissions, implying that they may also have important applications as DC materials.

Broadband down-conversion of near-infrared emission in Bi3+-Yb3+ co-doped Y3Al5O12 phosphors

An efficient near-infrared (NIR) down-conversion (DC) process has been demonstrated in Bi3+-Yb3+ co-doped Y3Al5O12 phosphors. The excitation spectra, emission spectra and decay curves were measured to prove the occurrence of energy transfer (ET) from Bi3+→Yb3+. Upon the excitation of UV photons, NIR emission has been obtained at 1028nm through the energy transfer from 3P1 energy level of Bi3+ to 2F5/2 energy level of Yb3+. Quantum efficiency related to Yb3+ concentration is calculated and the maximum efficiency reaches 138%. Our results suggested that these phosphors might have a potential application for the down-conversion process to improve the efficiency of Si-based solar cells.

The enhanced photocatalytic activity of Yb3+-Ho3+/Er3+ co-doped 3D BiOCl flower

A series of characteristic 3D flower-like BiOCl photocatalysts constructed by the self-assembling of BiOCl nanosheets substructures were synthesized through hydrothermal method, in which Ho3+/Yb3+ and Er3+/Yb3+ ion pairs were introduced to co-dope BiOCl to enhance photo-catalytic activity. Their structure, shape and morphology were not only characterized by power X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) and transmission electron microscopy (TEM), but also calculated the host electronic structure. The photocatalytic performances of Ho3+/Yb3+ and Er3+/Yb3+ co-doped BiOCl samples were enhanced greatly and evaluated by the degradation of rhodamine B (RhB) in aqueous solutions under the irradiation of stimulated sunlight and 450 nm blue light. To understand the potential reason, optical properties of the as-synthesized BiOCl samples were characterized by UV-vis diffuse reflectance spectra, up-conversion (UC) and down-conversion (DC) luminescence spectra were also investigated. The possible photo-catalytic mechanism was also raised, which develops a feasible method to improve the photocatalytic activity by combining with luminescence.

Rare Earth Doped Zinc Oxide Nanophosphor Powder: A Future Material for Solid State Lighting and Solar Cells

A comprehensive review of up-conversion (UP) and down-conversion (DC) or down shifting of rare earth (RE) doped zinc oxide (ZnO) nanophosphors is presented. Research interest in the development of RE3+ doped ZnO for UP and DC nanophosphors has been encouraged by the potential application of these materials in light emitting diodes and different types of photovoltaic cells. A range of remarkable characteristics, which are organized into different sections describing the structure, optical, and luminescence properties of these materials, are discussed in detail. Undoped ZnO has two characteristic emissions in the ultraviolet and visible regions related, respectively, to excitonic recombination and intrinsic defects. X-ray photoelectron spectroscopy (XPS) data demonstrated a correlation between the visible emission and intrinsic defects. In the case of the DC or shifting process, there was simultaneous emissions related to f → f transitions of RE ions and defects in ZnO host. These emissions were dependent o...

Studying of Perovskite Nanoparticles in PMMA Matrix Used As Light Converter for Silicon Solar Cell

AbstractThe nanoparticles of CH3NH3PbBr3hybrid perovskites were synthesized. These perovskite nanoparticles we embedded in polymethyl methacrylate (PMMA) in order to obtain the composite, which we used as light converter for silicon solar cells. It was shown that the composite emit the light with the intensity maximum at about 527 nm when exited by a short wavelength (300÷450 nm) of light. The silicon solar cells were used to examine the effect of down-conversion (DC) process by perovskite nanoparticles embedded in PMMA. For experiments, two groups of monocrystalline silicon solar cells were used. The first one included the solar cells without surface texturization and antireflection coating. The second one included the commercial cells with surface texturization and antireflection coating. In every series of the cells one part of the cells were covered by composite (CH3NH3PbBr3in PMMA) layer and second part of cells by pure PMMA for comparison. It was shown that External Quantum Efficiency EQE of the photovoltaic cells covered by composite (CH3NH3PbBr3in PMMA) layer was improved in both group of the cells but unfortunately the Internal Quantum Efficiency was reduced. This reduction was caused by high absorption of the short wavelength light and reabsorption of the luminescence light. Therefore, the CH3NH3PbBr3perovskite nanoparticles embedded in PMMA matrix were unable to increase silicon solar cell efficiency in the tested systems.

Energy transfer and 1.8 μm emission in Er3+/Tm3+ co-doped fluorogermanate glasses

The 1.8μm down-conversion emission properties of Er3+/Tm3+ co-doped fluorogermanate glasses are investigated under 980nm laser diode (LD) excitation in this paper. The glass properties are systematically evaluated by DSC, XRD, Raman techniques. The spectroscopic properties of Er3+ and Tm3+ including infrared down-conversion (DC) and visible up-conversion (UC) emissions are studied in detail. Meanwhile, the up-conversion emissions at 542nm, 654nm of Er3+ are suppressed with a high amount of Tm2O3 added. The Judd-Ofelt parameters and spontaneous transition probability of Tm3+ are illustrated for radiative properties. Besides, the absorption and emission cross sections of Tm3+ in Er3+/Tm3+ co-doped fluorogermanate glasses are provided as potential candidates for mid-infrared applications. The possible energy transfer mechanism is investigated via simplified energy level diagram, and energy transfer efficiency from Er3+ to Tm3+ is as high as 85.9%. In addition, the energy transfer parameters between Er3+ and Tm3+ are analyzed by the phonon sideband theory. The results indicate that the Er3+/Tm3+ co-doped fluorogermanate glasses have potential applications in mid-infrared lasers.

Dual-mode blue emission, paramagnetic properties of Yb3+–Tm3+ co-doped GdOCl difunctional nanostructures

A series of GdOCl:Yb3+, Tm3+ one-dimensional nanostructures with dual-mode [down-conversion (DC) and up-conversion (UC)] luminescence were successfully fabricated by electrospinning technique incorporated with double-crucible chlorination method. The samples have single-phase tetragonal structure with space group of P4/nmm. The diameter and width of GdOCl:10%Yb3+, 0.1%Tm3+ nanofibers and nanobelts are 212.84 ± 1.04 nm and 1.07 ± 0.03 μm, respectively. Excited by 357-nm ultraviolet (UV) light and 980-nm near-infrared (NIR) light, Yb3+ and Tm3+ ions co-doped GdOCl nanostructures exhibit bright blue emission. The mechanism of UC emission is determined to be three-photon process. The energy transfer processes from Yb3+ to Tm3+ are discussed in detail. Moreover, the as-obtained products possess paramagnetic properties at ambient temperature. The type of difunctional one-dimensional nanomaterials has promising applications in anti-counterfeiting, drug delivery, solid state lasers, biolabels and light emitting diodes (LEDs).

Visible quantum cutting in green-emitting BaF2: Gd3+, Tb3+ phosphor: An approach toward mercury-free lamps

Visible quantum cutting (QC) has been observed in green emitting BaF2 co-doped with Gd3+, Tb3+ phosphor via down-conversion (DC) synthesized by wet chemical method. Powder X-ray diffraction (XRD) analysis shows structural purity of synthesized phosphors. The excitation (PLE) and PL spectra in the vacuum ultraviolet (VUV) or UV region were measured with the help of 4B8-VUV spectroscopy experimental station of the Beijing Synchrotron Radiation Facility (BSRF). In the QC process, one VUV–UV photon absorbed is cut into more than one visible photons emitted by Tb3+ through cross relaxation (CR) and direct energy transfer (DET) between Tb3+ and Tb3+ or Tb3+ and Gd3+, depending on the excitation wavelength. From the emission spectra monitored at different wavelength excitation, the two-step energy transfer process is investigated and theoretically calculated quantum efficiency observed 148% and 177% at the excitation wavelength of 174 nm and 219 nm respectively.

Self-crystallized novel transparent Na5Yb9F32: Er3+ glass-ceramics for optical thermometry and spectral conversion

Novel self-crystallized transparent Na5Yb9F32: Er3+ glass-ceramics (GCs) were successfully elaborated through high temperature melt-quenching route for the first time. X-ray diffraction (XRD), transmission electron microscopy (TEM), selected-area electron diffraction (SAED) and photoluminescence emission spectra confirmed that the Na5Yb9F32 nanocrystals (NCs) were well-formed without any additional phase. In addition, X-ray photoelectron spectroscopy (XPS) was studied for investigating valence states of elements in the Na5Yb9F32: Er3+ GCs and it was suggesting that Er3+ ions was doped into the Na5Yb9F32: Er3+ GCs. Interestingly, the XRD patterns and TEM images demonstrate that the Na5Yb9F32 NCs have already formed during melt-quenching process without any further heat treatment. Due to improved crystallinity, reduced surface-to-volume ratio and more Er3+ incorporation into NCs after further heat treatment, both up-conversion (UC) and down-conversion (DC) show enhanced luminescence intensity after heat treatment. The emission color of Na5Yb9F32 GCs changed under different ultraviolet excitation wavelength was addressed and interpreted by photoluminescence. Furthermore, via the fluorescence intensity ratio (FIR), the temperature-dependent green UC emissions of Na5Yb9F32: Er3+ GCs were studied under 980 nm laser excitation. Provided with broad operating temperature range (300–773 K), large energy gap of thermal coupled energy levels (835 cm−1) and high sensitivity (1.33% K−1 at 300 K), the Na5Yb9F32: Er3+ GCs may have potential application in temperature senor.

Organic additive assisted hydrothermal synthesis and photoluminescence properties of CeF3:Tb3+ and NaCeF4:Tb3+ nanoparticles

A series of Tb3+ doped CeF3 and NaCeF4 nanoparticles with different morphology and dimension were synthesized via hydrothermal method. Different organic additives, including sodium dodecyl sulfonate (SDS), polyvinylpyrrolidone (PVP), cetyltrimethyl ammonium bromide (CTAB), oleic acid (OA), polyethylene glycol (PEG), trisodium citrate (Cit) were introduced to control the crystallite size and morphology. Powder X-ray diffraction (PXRD), fourier transform infra-red spectra (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and down-conversion (DC) photoluminescence spectra were used to characterize the samples. The emission peaks of all the prepared samples centered at 490, 545, 585 and 621 nm which can be ascribed to the 5D4→7FJ (J = 6, 5, 4, 3) transitions respectively of Tb3+ ion. However, emission intensities are strongly controlled by morphology and particle sizes which are influenced by different organic additives used in synthesis. Moreover, the crystal growth process was monitored through a series of time-dependent experiments and a possible formation mechanism has been proposed.

Dual-mode blue emission, enhanced up-conversion luminescence and paramagnetic properties of ytterbium and thulium-doped Ba2GdF7 multifunctional nanophosphors

A series of Ba2GdF7:Yb3+, Tm3+ nanophosphors (NPs) with dual-mode (down-conversion (DC) and upconversion (UC)) luminescence were successfully prepared by hydrothermal method at 180°C. The NPs have sphere-like morphology and cubic structure. Under the excitation of ultraviolet 355nm and near-infrared 980nm, Yb3+ and Tm3+ ions co-doped Ba2GdF7 phosphors exhibit bright blue dual-mode emission. The mechanism of UC emissions was determined three-photon absorption. The energy transfer processes from Yb3+ to Tm3+ were discussed in detail. The up-conversion luminescence of Ba2GdF7:Yb3+/Tm3+ nanophosphors were enhanced by introducing the sensitizer Yb3+ ions and modifying the cetyltrimethylammonium bromide (CTAB) surfactant, respectively. Moreover, the as-prepared samples exhibit paramagnetic properties at room temperature. This type of multifunctional nanophosphors have promising applications in anti-counterfeiting, drug delivery, solid state lasers, biolabels, MRI, light emitting diodes (LEDs).

Effects of down-conversion CeO2:Eu3+ nanophosphors in perovskite solar cells

In this work, enhanced photovoltaic performance and light stability of perovskite solar cells (PSCs) was achieved by applying down conversion (DC) CeO2:Eu3+ nanophosphor—TiO2 composite electrodes and the related mechanism are reported. High-yield CeO2:Eu3+ nanocrystals were synthesized by a simple hydrothermal method with combinational use of trisodium phosphate dodecahydrate and sodium hydroxide. Uniform and efficient CeO2:Eu3+ nanophosphors were prepared at an optimized reaction time. The optimal CeO2:Eu3+ nanophosphors were 70 nm in size, with octahedral and mirrorlike facets that provided excellent DC luminescence. The CeO2:Eu3+ nanophosphors grown at the optimal conditions were incorporated into mesoporous TiO2 layers of PSC devices. The PSC device with the CeO2:Eu3+—TiO2 composite electrode exhibited an energy conversion efficiency of 10.8%, which improved efficiency by 35% relative to the referenced one with undoped CeO2 nanocrystals. PSC devices added with undoped and doped CeO2 nanocrystals exhibited significantly better stability toward UV light compared to the bare TiO2 based PSC cell. The fundamental optics behind light propagation and absorption in perovskite solar cell and concept of using DC nanophosphors to improve the device performance has been explored. In this study, an attempt was made to elucidate the multi-roles of DC nanoconverters in mesoporous TiO2 based PSCs.