Efficient Nonradiative Energy Transfer Research Articles

Photo- and X-ray Induced Cytotoxicity of CeF3-YF3-TbF3 Nanoparticle-Polyvinylpyrrolidone-"Radachlorin" Composites for Combined Photodynamic Therapy.

The Ce0.5Y0.35Tb0.15F3 nanoparticles with a CeF3 hexagonal structure were synthesized using the co-precipitation technique. The average nanoparticle diameter was 14 ± 1 nm. The luminescence decay curves of the Ce0.5Y0.35Tb0.15F3 nanoparticles (λem = 541 nm, 5D4-7F5 transition of Tb3+) conjugated with Radachlorin using polyvinylpyrrolidone coating as well as without Radachlorin were detected. Efficient nonradiative energy transfer from Tb3+ to the Radachlorin was demonstrated. The maximum energy transfer coefficients for the nanoparticles conjugated with Radachlorin via polyvinylpyrrolidone and without the coating were 82% and 55%, respectively. The average distance between the nanoparticle surface and Radachlorin was R0 = 4.5 nm. The best results for X-ray-induced cytotoxicity were observed for the NP-PVP-Rch sample at the lowest Rch concentration. In particular, after X-ray irradiation, the survival of A549 human lung carcinoma cells decreased by ~12%.

Visible and infrared photoluminescence of Er-doped AlN films: Excitation of Er ions via efficient nonradiative energy transfer from the host level

Aluminum nitride (AlN) is a multifunctional semiconductor. AlN doped with rare earth ions has broad application prospects in monochromatic lighting, color display, laser medium, medical treatment, etc. In this paper, an Er3+-doped AlN film has been prepared by radio frequency magnetron sputtering and characterized by surface morphology, chemical composition and photoluminescence (PL), focusing on the emission mechanism of Er3+ in the AlN host. The films show PL in a wide range of the visible (540, 560 and 668 nm) and near-infrared (816, 869, 985 and 1534 nm) ranges. It has been found a certain energy transfer bridge between Er3+ and AlN defect-related optical transitions. At 532 nm excitation, VAl-ON vacancy-oxygen complex in the AlN host efficiently absorbs photons, then, nonradiative energy transfer (NRET) occurs from the defect levels to the levels of Er3+ since they are in resonance. Since there is a resonance of a donor emission level and an acceptor absorption level, Förster resonance energy transfer (FRET) occurs with the transfer efficiency about 51%. This results in a very strong enhancement of excitation of the 4f related PL. On the contrary, optical excitation at other energies results in a low intensity of the Er3+ PL. As a matter of facts, a strong absorption of the AlN host and the FRET-enabling resonance of donor-acceptor levels allow for a great enhancement of the PL efficiency of Er3+ ions. The results show that the impurity defect state of AlN has an important influence on the Er3+ luminescence efficiency.

(INVITED)Direct laser writing of visible and near infrared 3D luminescence patterns in glass

We report the fluorescent properties of 3D localized structure with size near the diffraction limit induced by femtosecond direct laser writing (DLW) in Yb3+ and silver-containing phosphate glass. The homogenous dispersion of the silver ions and Yb3+ ions in the glass matrix before DLW was evidenced using photo-luminescent spectroscopy and time-resolved spectroscopy. Using high repetition rate femtosecond DLW, the inscription of 3D visible and near-infrared fluorescent patterns formed by co-localization of silver cluster and Yb3+ ions was demonstrated. The local refractive index change associated with the formation of silver clusters is dependent on the laser irradiance. Confocal micro-luminescent spectroscopy for excitation wavelength in the visible range shows efficient emission of Yb3+ only on DLW induced 3D fluorescent patterns. This finding demonstrated the ability to perform thanks to DLW laser a resonant efficient nonradiative energy transfer from silver clusters to Yb3+ and allows 3D writing of near-infrared luminescence.

MoS2 monolayer quantum dots on a flake: Efficient sensitization of exciton and trion photoluminescence via resonant nonradiative energy and charge transfers

MoS2 monolayer quantum dots (1L-QDs) are hybridized on 1L MoS2 on SiO2/Si. The exciton and trion photoluminescence (PL) of the 1L-QD/MoS2 hybrid is studied in comparison to bare 1L MoS2. The 1L-QDs have a round-like shape with an average lateral size of 3 nm, which results in interband absorption and PL within 2.3–3.5 eV. The bare flake shows the A and B exciton PL bands, overlapped with a weak trion band. The 1L-QD/MoS2 hybrid comprises the emission bands so that the 1L-QD PL intensity is not altered, but the flake PL is tremendously enhanced. This effect of sensitization depends on the PL excitation energy: 6.4 times under UV excitation involving the transitions between the valence band and the excited states in the conduction band of the 1L-QDs and 2.7 times under blue light excitation involving interband absorption between the 1L-QD quantum states. The strongest effect is explained by an efficient nonradiative energy transfer (NRET), similar to Förster resonance energy transfer, and possible charge transfer from the resonant levels in the donor 1L-QDs to the levels in the acceptor MoS2 flake. On the contrary, exciting e-h pairs between the 1L-QD quantum states, they rapidly recombine there, weakening NRET.

Tunable Fluorescence in Two-Component Hydrogen-Bonded Organic Frameworks Based on Energy Transfer.

A dumbbell-shaped compound (TPAD) with four 2,4-diaminotriazine moieties as H-bond units and a benzene ring as a bridge group was found to form hydrogen-bonded organic frameworks (HOFs) with strong cyan fluorescence. An energy acceptor, 6,6',6″,6‴-(((benzo[c][1,2,5]thiadiazole-4,7-diylbis-(4,1-phenylene))bis(azanetriyl))tetrakis(benzene-4,1-diyl))tetrakis(1,3,5-triazine-2,4-diamine) (BTAD), with the same molecular skeleton as TPAD and a longer emission wavelength could homogeneously distribute within the framework of TPAD through occupying the locations of TPAD. As a result, two-component HOFs (TC-HOFs) were formed. The nonradiative energy transfer from TPAD as the donor to BTAD as the acceptor happens within frameworks owing to the efficient spectral overlap between the emission of TPAD and the absorption of BTAD. Moreover, the emission wavelengths and colors of TC-HOFs could be easily and continuously modulated by the content of the acceptor. The fluorescence color changed from cyan to orange when the content of BTAD gradually increased. This finding affirms that TC-HOFs with continuously adjustable composition can be constructed from two molecules with the same molecular skeleton, and highly efficient nonradiative energy transfer may happen in porous TC-HOFs. To the best of our knowledge, these TC-HOFs are the first example of TC-HOFs involved in energy transfer.

InP-Bovine Serum Albumin Conjugates as Energy Transfer Probes.

The use of indium phosphide (InP) quantum dots (QDs) as biological fluorophores is limited by the low photoluminescence quantum yield (ϕPL) and the lack of effective bioconjugation strategies. The former issue has been addressed by introducing a strain relaxing intermediate shell such as ZnSe, GaP etc. that significantly enhances the ϕPL of InP. Herein, we present an effective strategy for the conjugation of emissive InP/GaP/ZnS QDs with a commonly used globular protein, namely bovine serum albumin (BSA), which generate colloidally stable QD bioconjugates, labeled as InP-BSA and demonstrate its use as energy transfer probes. The conjugate contains one protein per QD, and the circular dichroism spectra of BSA and InP-BSA exhibit similar fractions of α-helix and β-sheet, reflective of the fact that the secondary structure of the protein is intact on binding. More importantly, the fluorescence polarization studies corroborate the fact that the bound protein can hold a variety of chromophoric acceptors. Upon selectively exciting the InP-BSA component in the presence of bound chromophores, a reduction in the emission intensity of the donor is observed with a concomitant increase in emission of the acceptor. Time-resolved investigations further confirm an efficient nonradiative energy transfer from InP-BSA to the bound acceptors.

Photophysical and morphological properties of spin-coated and self-assembled carbazole derivative thin films

In this work, single-layered, bi-layered and tri-layered poly(vinyl-carbazole) (PVK) thin films were produced by spin-coating and self-assembling techniques and their morphological and photophysical properties were determined by time-resolved fluorescence spectroscopy, atomic force microscopy (AFM) and fluorescence microscopy. The effect of distinct aggregates formed in thin films on their photophysical and morphological properties was determined, evidencing that procedure control is essential to determine PVK thin film application. It was found that sandwich excimers are dominant in self-assembled films, evidenced by longer fluorescence lifetimes and red-shifted emissions, while in spin-coated films, shorter fluorescence lifetimes evidenced more efficient non-radiative energy transfer. AFM showed that consecutive deposited layers result in more uniform, thinner films when produced by spin-coating, but showing aggregation heterogeneity as evidenced by fluorescence spectroscopy. Yet, self-assembled films are rough, heterogeneous and thicker, showing prevalence of less variety of aggregates. These are crucial findings to address PVK application.

Three-Dimensional High Spatial Localization of Efficient Resonant Energy Transfer from Laser-Assisted Precipitated Silver Clusters to Trivalent Europium Ions

We report on the 3D precipitation, using a direct laser writing approach, of highly fluorescent silver clusters in a Eu3+-doped silver-containing zinc phosphate glass. Micro-spectroscopy of fluorescence emission shows the ability to continuously adjust the local tri-chromatic coordinates in the CIE (Commission Internationale de l’Éclairage) chromaticity diagram between red and white colors, thanks to the laser-deposited dose and resulting tunable combination of emissions from Eu3+ and silver clusters. Moreover, continuous-wave and time-resolved FAST-FLIM spectroscopies showed a significant enhancement of the fluorescence emission of Eu3+ ions while being co-located with UV-excited laser-inscribed silver clusters. These results demonstrate the ability to perform efficient resonant non-radiative energy transfer from excited silver clusters to Eu3+, allowing such energy transfer to be highly localized on demand thanks to laser inscription. Such results open the route to 3D printing of the rare earth ions emission in glass.

Thermal quenching and color tuning of Ce3+, Mn2+ co-doped Ba2LuAl3Si2O12 for high quality white-LED

Good thermal stability and high quantum efficiency (QE) are desirable properties for phosphors applied in white light-emitting diodes field. In this work, a Ce3+ doped phosphor Ba2LuAl3Si2O12:Ce3+ (BaLuAS:Ce3+) was designed and successfully obtained. Structure analysis of Ba2LuAl3Si2O12 indicates that it adopts garnet structure and crystallizes in space group Ia¯3d (No.230) of the cubic system. The wavelength-dependent photoluminescence emission property and the mechanism of concentration quenching effect of BaLuAS:xCe3+ were investigated systematically. The PL emission exhibits high thermal quenching resistance with the quenching temperature (T50%) reaching up to 673 K (400 °C). By measuring thermoluminescence, the thermal ionization process was discussed. To compensate for the lack of orange-red emission region and avoid using multiple phosphors, Mn2+ ions were introduced into the host. The remarkable enhancements of the orange band are attributed to an efficient nonradiative energy transfer from Ce3+ to Mn2+ ions, which has been testified by the photoluminescence spectra and fluorescence decay dynamics. The w-LED fabrication results suggest that the broad emission of BaLuAS:Ce3+, Mn2+ is suitable for applying in high-quality warm w-LED.

Visible emission and energy transfer in Tb3+/Dy3+ co‐doped phosphate glasses

AbstractIn this work, we systematically study the spectroscopic properties of Tb3+/Dy3+ co‐doped phosphate glasses in the visible spectral region and explore the sensitization role of Dy3+ in the enhancement of visible fluorescence of Tb3+ ions. Judd‐Ofelt parameters Ω2 and Ω4/Ω6 of the phosphate glass as host for Tb3+ are calculated as 21.60 × 10‐20 cm2 and 0.73, respectively, based on the measured spectral absorption. Multiple energy transfer (ET) routes from Dy3+ to Tb3+ and their efficiencies are characterized, and the enhanced fluorescence properties of Tb3+ are investigated, including the emission spectral strength and the spontaneous emission lifetime as functions of Dy3+ doping concentration. The efficient nonradiative ET processes between Dy3+ and Tb3+ allow a moderate concentration level of Tb3+ to achieve favorably stronger spectral absorption at blue and ultraviolet wavelengths. Tb3+/Dy3+ co‐doped phosphate glass shows promising potential for phosphors and lasing operation at visible wavelengths.

Downshifting of highly energetic photons and energy transfer by Mn-doped perovskite CsPbCl3 nanocrystals in hybrid organic/silicon nanostructured solar cells

Abstract The downshifting of highly energetic photons in the ultraviolet region has the benefit of extending the spectral response and decreasing the thermalization effect in Si-related solar cells. Herein, we report low-cost hybrid organic/inorganic solar cells with minimized spectral losses with directly-deposited Mn-doped perovskite CsPbCl3 nanocrystals (NCs) on the surface of Si nanotips with PEDOT:PSS acting as the hole transporting and passivating layer. The CsPbCl3 NCs act as highly efficient radiative and non-radiative energy transfer centers. Manganese doping in CsPbCl3 NCs also drastically enhances photoluminescence quantum yields due to the charge transfer of photoinduced excitons from the CsPbCl3 host to the dopant Mn2+ centers. Finally, the Mn doped CsPbCl3 NCs enhance the cell properties and give a high power conversion efficiency of 13.48%.

Microwell plates coated with graphene oxide enable advantageous real-time immunosensing platform

Immunoassays are fundamental analytical tools in molecular diagnostics, therapy monitoring and drug discovery. Nevertheless, they often take around 6 h and require cumbersome procedures. We introduce a breakthrough in immunosensing based on the photoluminescence quenching capabilities of graphene oxide (GO) and the versatile format offered by the famous microwell plates. Taking advantage of the highly efficient non-radiative energy transfer occurring between photoexcited fluorophores (donors) and GO (acceptor), we discovered that flurophore-labelled antibodies (Fl-Abs) are quickly and strongly quenched by the studied GO-coated microwell, whereas Fl-Abs complexed with the respective analyte are weakly quenched by the same surface due to the low affinity between the GO-coated surface and the relatively long distance between these photoluminescent complexes and the GO-coated surface. In doing so, we developed a conceptually innovative single-step immunosensing platform, avoiding blocking, separation and washing steps and exploiting a single antibody. Importantly, the biosensing response can be interrogated in real time. This leads to an advantageous immunodetection phenomenon which is observable in few minutes (e.g. 5 min). The resulting highly transformative biosensing platform operates with different photoluminescent agents and different analytes. Besides, this biosensing platform was demonstrated to operate with real samples of human urine doped with different concentrations of prostate specific antigen.

Optical and structural properties of CsPbBr3 perovskite quantum dots/PFO polymer composite thin films

The aim of this study is to investigate the optical and structural properties of polymer/perovskite quantum dots (QDs) composite thin films and estimate the applicability of using these blends as active materials in photonic devices. A solution has been utilized, which is processed based on conjugated polymer and perovskite QDs composite films. The incorporation of CsPbBr3 QDs, with various weight ratios, influences the structure of the thin films, as proven by several techniques. The results of the study showed that the surface of the poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO)/CsPbBr3 thin films improved, when compared to that of the pristine CsPbBr3 thin film. The increase in the steepness parameter and decrease in both the energy gaps and Urbach tail, upon the increment of CsPbBr3 QDs, can be attributed to the decrease in the localized density of electronic states within the forbidden band gap of the hybrids. The overlap between the absorption spectrum of PFO and emission spectrum of CsPbBr3 QDs, and the enhancement in the emission peak of CsPbBr3 in the blends, confirmed the efficient non-radiative energy transfer between them.

Luminescence of GdF3:Pr:Yb and YF3:Pr:Yb Solid Solutions Synthesized by Crystallization from the Melt

Spectral and luminescence characteristics of GdF3:Pr:Yb and YF3:Pr:Yb solid solutions synthesized by crystallization from the melt were investigated. Down-conversion luminescence of Yb3+ in the region of 2F5/2 → 2F7/2 transitions with 445-nm excitation was studied. The energy-transfer coefficient from Pr3+ to Yb3+ was <80% for concentration ratios Pr/Yb 0.5/10.0 and 1.0/10.0 for GdF3 and 0.5/10.0 for YF3. The absolute values of Pr3+ and Yb3+ luminescence quantum yields in the region of the greatest crystalline-silicon photosensitivity were low because of highly efficient nonradiative energy transfer. The quantum yield was <1% for Yb3+ intrinsic luminescence and <4% for total luminescence in the range 800–1050 nm (for concentration ratio Pr/Yb = 0.5/1.0 in GdF3 matrix). The low quantum yield was a consequence of the complex energy-exchange pattern between Yb3+ and Pr3+ ions, which was largely influenced by the proximity of 1G4 and 2F5/2 energy states of Pr3+ and Yb3+, respectively, in these matrices. This opened an additional pathway for nonradiative decay of Yb3+ excited states and enabled cross-relaxation between 3P0 → 1G4 transitions of Pr3+ and 2F5/2 → 2F7/2 transitions of Yb3+ that increased the lifetime of the Pr3+ 3P0 state.

Co-solubilization of polycyclic aromatic hydrocarbon mixtures in aqueous micellar systems and its correlation with FRET for enhanced remediation processes.

Surfactant enhanced remediation (SER) is an effective approach for decontaminating the PAH polluted soils. Solubilization and Cosolubilization of Phenanthrene (Ph), Pyrene (Py) and Perylene (Pe) as single, binary and ternary mixtures have been studied employing cationic (CTAB), anionic (SDS), non-ionic surfactant (Brij 30) and block copolymer (P123) micelles. In the single solute solubilization studies, solubility of Pe follows the order Brij 30 > CTAB > SDS whereas Ph or Py followed the order of CTAB > Brij 30 > SDS. In the cosolubilization studies, an increase, decrease or no change in the mutual solubility of PAHs was observed. Synergism in solubilization was observed most in P123 in both binary and ternary PAH mixture where more PAHs could get solubilized in the dense micellar shell region, thereby enhancing the micellar core volume leading to enhanced solubilization of PAHs. The solubilizates as pairs (Ph-Pe and Py-Pe) were further tested for any possible energy transfer in presence of surfactant based restricted host environments using spectrofluorometry and spectrophotometry. Based on the solubilization and cosolubilization an efficient non-radiative energy transfer (FRET) was observed between Ph/Py (donor) and Pe (acceptor) in the non-ionic surfactant system as well as in CTAB-Brij 58 mixed system. The results of this work may improve the effective utilization of surfactants in their correct evaluation for the removal of PAHs from contaminated soils or aquifers treated with SER technology.

On the origin of the enhancement of defect related visible emission in annealed ZnO micropods

We report an in-depth analysis of ZnO micropods emission. A strong correlation between defect and interband emissions is observed. ZnO micropods were grown using low-temperature chemical bath deposition (CBD). ZnO micropods exhibited perfectly-crystalline hexagonally-shaped facets with various numbers of branches. Raman studies showed that ZnO micropods contained trapped zinc hydroxide (OH) and imidogen (NH) defects that originate from the precursor solution used in the CBD technique. These defects were evacuated by thermal annealing, leading to the recrystallization in the volume of the micropods and the formation of structural defects at their surface, as attested by scanning electron microscopy and X-ray diffraction. More importantly, the thermal annealing was accompanied by a breakdown of the NH defects, which resulted in a nitrogen doping of the ZnO micropods. The structural changes as well as the nitrogen doping resulted in a drastic change in the photoluminescence (PL) spectrum of the ZnO micropods that exhibited a stronger free exciton UV emission as well as a stronger visible (white) emission. An in-depth low-temperature PL study of both UV and visible emission reveals a strong interplay between the structural-defect bound excitonic UV emission (Y-band) and the deep donor (visible) emission, which suggests a rather complex emission mechanism involving an efficient nonradiative energy transfer between the Y-band states and defect states leading to the enhanced visible emission of ZnO micropods after high temperature annealing.

(Invited) Enhancement of Triplet-Triplet Annihilation-Based Upconversion Emission By Localized Surface Plasmon Resonance

The upconversion emission systems using triplet-triplet annihilation (TTA-UC emission) has attracted much attention because these systems can be driven by a noncoherent light with low intensity (e.g. sunlight). Namely, the achievement of efficient TTA-UC emission systems directly leads to the development of high-performance solar energy devices. On the other hand, since the Dexter energy transfer between the sensitizers and the emitters is contained in the process of TTA-UC emission, the emission efficiency is quite low in solid state. We have tried to enhance the emission in solid state TTA-UC systems by interacting with the localized surface plasmon (LSP) resonance of metal nanoparticles. The anisotropic triangular silver nanoplates (silver nanoprisms: AgPRs) were employed as a plasmonic metal nanoparticle because of the generating wavelength tunability of their LSP resonance and the generation of strong local electromagnetic fields. The hybrids of AgPRs and TTA-UC systems were fabricated by spin-coating the polymer solution containing the sensitizer (palladium(II) tetraphenyltetrabenzoporphyrin: Pd-TPTBP) and the emitter (9,10-bis(phenylethynyl)anthracene: BPEA) onto the AgPRs-immobilized glass plates. When the LSP resonance band of AgPRs spectrally overlapped with both the photoexcitation wavelength of Pd-TPTBP and the fluorescence band of BPEA, the TTA-UC emission was efficiently enhanced. It is reasonable to consider that the former spectral overlap provides the enhancement of TTA-UC emission through the photoexcitation enhancement of Pd-TPTBP (Figure 1). In addition, the threshold excitation intensity (the figure-of-merit in TTA-UC systems) significantly decreased by overlapping the LSP resonance band with the photoexcitation wavelength. Also, it was suggested by the fluorescence lifetime measurements that the enhancement of TTA-UC emission caused by overlapping with the fluorescence band was induced by the efficient nonradiative energy transfer from the singlet excited BPEA to the LSP of AgPRs (Figure 1). On the other hand, when the LSP resonance band overlapped well with the phosphorescence band of Pd-TPTBP, the TTA-UC emission was rather quenched. These results suggest that the nonradiative energy transfer by the LSP resonance from the triplet excited Pd-TPTBP to the LSP became dominant, as compared with the triplet-triplet energy transfer from the Pd-TPTBP to the BPEA. Namely, it was demonstrated that the LSP resonance of AgPRs has both of the positive and negative effects on the solid state TTA-UC emission systems.[1] Furthermore, we investigated the optical interaction between the singlet excited palladium porphyrin and the LSP resonance of AgPRs. Consequently, we will discuss the detailed effects of LSP resonance of the AgPRs on the complicated TTA-UC emission processes. [1] S. Jin, K. Sugawa et al., ACS Photon., 2018, 5, 5025-5037. Figure 1

Photophysics of "Floppy" Dyads as Potential Biomembrane Probes.

In the study a dyad (C6 probe), constructed of two dyes with highly different hydrophobicities, was investigated by steady-state and time-resolved spectroscopic techniques in chloroform, methanol, and in phospholipid vesicles, respectively. The dyad was built on two dyes: the lipophilic benzo[a]pyrene (BaP) and the hydrophilic sulforhodamine B (SRB). The dyes were linked via a short, but flexible alkyl chain (six C-atoms). Based on their spectroscopic properties, BaP and SRB showed a very efficient non-radiative resonance energy transfer in solution. Incorporation into a lipid bilayer limited the relative flexibility (degree of freedom) between donor and acceptor and was used for the investigation of fundamental photophysical aspects (especially of FRET) as well as to elucidate the potential of the dyad to probe the interface of vesicles (or cells). The location of the two dyes in vesicles and their respective accessibility for interactions with dye-specific antibodies was investigated. Based on the alteration of the anisotropy, on the rotational correlation time as well as on the diffusion coefficient the incorporation of the C6 probe into the vesicles was evaluated. Especially the limitation in the relative movements of the two dyes was considered and used to differentiate between potential parameters, that influence the energy transfer in the dyad. Transient absorption spectroscopy (TAS) and pulsed-interleave single molecule fluorescence experiments were performed to better understand the intramolecular interactions in the dyad. Finally, in a showcase for a biosensing application of the dyads, the binding of an SRB-specific antibody was investigated when the dyad was incorporated in vesicles. Graphical Abstract.

Photovoltaic Effect of a Ferroelectric-Luminescent Heterostructure under Infrared Light Illumination.

In this report, a ferroelectric-luminescent heterostructure is designed to convert infrared light into electric power. We use BiFeO3 (BFO) as the ferroelectric layer and Y2O3:Yb,Tm (YOT) as the upconversion layer. Different from conventional ferroelectric materials, this heterostructure exhibits switchable and stable photovoltaic effects under 980 nm illumination, whose energy is much lower than the band gap of BFO. The energy transfer mechanism in this heterostructure is therefore studied carefully. It is found that a highly efficient nonradiative energy transfer process from YOT to BFO plays a critical role in achieving the below-band-gap photon-excited photovoltaic effects in this heterostructure. Our results also indicate that by introducing asymmetric electrodes, both the photovoltage and photocurrent are further enhanced when the built-in field and the depolarization field are aligned. The construction of ferroelectric-luminescent heterostructure is consequently proposed as a promising route to enhance the photovoltaic effects of ferroelectric materials by extending the absorption of the solar spectrum.

Highly Efficient Nonradiative Energy Transfer from Colloidal Semiconductor Quantum Dots to Wells for Sensitive Noncontact Temperature Probing

Highly Efficient Nonradiative Energy Transfer from Colloidal Semiconductor Quantum Dots to Wells for Sensitive Noncontact Temperature Probing