Low-temperature Photoluminescence Research Articles

Structural and temperature-dependent photoluminescence properties of NaBaBO3:Ce3+,Tb3+ phosphors synthesized using the combustion method

This study explores the structural and temperature-dependent photoluminescence of Ce3+ and Tb3+ doped NaBaBO3 phosphors, synthesized via combustion. Analysis of their crystal structures confirmed excellent alignment with the standard PDF#98–008-0110. Investigation into both room and low-temperature photoluminescence revealed that the dopants have a significant effect on emission spectra. Ce3+-doped samples exhibited excitation peaks at 275 nm and 358 nm, leading to a primary emission at 419 nm, with enhanced low-temperature emission suggesting reduced non-radiative processes. Tb3+-doped phosphors showed excitation from 250 to 377 nm and emissions from blue to deep red, including strong green emission at 550 nm due to 5D4→7F5 transitions. Optimal doping was found at 1 mol% for Ce3+, while Tb3+ showed increased luminescence up to 3 mol%, with concentration quenching observed beyond these points. The study indicates dipole–dipole interactions dominate Ce3+ concentration quenching, whereas Tb3+ involves both electric dipole and quadrupole interactions. This analysis provides insights into enhancing luminescent efficiency and suggests NaBaBO3:xCe3+,Tb3+ phosphors' potential in advancing white LED technology, highlighting their stable luminescent properties at low temperatures.

Low-temperature photoluminescence measurement with a micromachined Joule-Thomson cooler

This study evaluates the effectiveness of micromachined Joule-Thomson (MJT) cooling for photoluminescence (PL) materials. Achieving low temperatures is crucial for enhancing PL performance in semiconductors. However, the commonly used liquid nitrogen (LN2) cryostats require frequent refills, hindering their long-term operation. The MJT cooler offers a potential solution by enabling integration with devices and longer operating time. To validate its effectiveness, this study conducted low-temperature PL measurements using a nitrogen MJT cooler. A MAPbI3 thin film was used as the characterization sample owing to its clear PL mechanism. The experiment successfully preserved its temperature-dependent PL property, with an observed orthorhombic phase-change phenomenon between 155-165 K. Furthermore, the system demonstrated short cool-down time (<1 h), minimal temperature impact from laser stimulus (<±0.1 K), sample storage stability, and low coolant consumption.

The effect of FeGa (0/–) level presence on material properties in dilute AlxGa1−xN layers

AlxGa1−xN epilayers are used as the basis of ultraviolet LEDs and detectors. The trap states produced by defects and impurities can play a key role in the device performance. In this work, conventional deep-level transient spectroscopy, photoluminescence (PL), and secondary ion mass spectrometry have been used to characterize a deep-level trap termed as E3 in dilute AlxGa1−xN (x &amp;lt; 0.063) epilayers grown by metal-organic vapor phase epitaxy (MOVPE) on highly conductive ammono-GaN substrates. The AlxGa1−xN epilayers were doped with silicon to about 3 × 1016 cm−3. The electrical and the optical measurements were conducted on Ni/Au Schottky barrier diodes and virgin samples, respectively. First, we observed a general trend that the E3 (FeGa) electron trap concentration significantly changes along the wafers in AlxGa1−xN layers that is fully consistent with previously reported results for GaN materials grown by the MOVPE technique. Second, we report that the activation energies for electron emission for the E1 and E3 traps in dilute AlxGa1−xN exhibit linear variations with Al content. Moreover, low-temperature PL results show a proportional relation between the intensity of the line with its maximum at 1.299 eV and concentration of residual Fe impurity. Finally, we discuss how the presence of defects resulting from Fe contamination may result in degradation of AlxGa1−xN-based devices.

The Characteristics of Luminescence from High-Temperature- and High-Pressure-Treated Diamonds

High-temperature and high-pressure (HTHP)-treated diamonds have attracted attention all over the world due to their vivid colors. In order to explore a new method for the rapid and non-destructive identification of HTHP-treated diamonds, in this paper, five IaAB-type diamonds yielded in Russia were selected as the research object and treated with HTHP. The HTHP-treated diamonds were investigated by DiamondViewTM, cathodoluminescence, micro-infrared spectrometry (micro-IR), low-temperature photoluminescence (PL) spectrometry, and three-dimensional (3D) fluorescence spectrometry. The results show that under DiamondViewTM and cathode rays, the five samples were all non-phosphorescent with different luminous patterns, such as regular annular bands, multiple groups of intersecting linear stripes, or jagged stripes. In the low-temperature PL spectra, most HTHP-treated diamonds exhibited stronger luminescence peaks at 637 nm compared to 575 nm. But there were also exceptions, such as the purple-red sample showing the opposite luminescence peak. In the 3D fluorescence spectrum of the HTHP-treated diamonds, the fluorescence peak mainly appeared in the range of 440–450 nm, accompanied by a broad band of 350–500 nm and even longer wavelengths. Meanwhile, some samples also exhibited fluorescence peaks at longer wavelengths, such as 353 nm, 676 nm, and 665 nm. These results make it possible to identify HTHP-treated diamonds by using luminescence characteristics, providing a new method for the non-destructive and rapid detection of HTHP-treated diamonds.

Mn-doped perovskite quantum dots with thermal stability synthesized at room temperature

All inorganic perovskite quantum dots (PQDs) have been studied extensively because of their excellent photoelectric properties. However, its poor stability and lead toxicity limit its practical application. At the same time, the complex synthesis conditions of the hot injection method also limited the preparation of large quantities. Here, we have successfully synthesized Mn-doped CsPb(Cl/Br)3 PQDs with excellent thermal stability at room temperature by a simple supersaturation crystallization method. The synthesized Mn-doped CsPb(Cl/Br)3 PQDs has good homogeneity and crystallinity. Meanwhile, Mn-doped CsPb(Cl/Br)3PQDs maintains the same crystal structure as CsPb(Cl/Br)3 PQDs. Importantly, it was found that the activation energy of CsPb(Cl/Br)3 PQDs after manganese doping increased from 65.1 meV to 222.8 meV through the high and low temperature PL test of 80 K–500 K. The crystal structure of CsPb(Cl/Br)3 PQDs is more stable due to the introduction of manganese ion, and the thermal stability is significantly improved. In this study, manganese doped CsPb(Cl/Br)3 PQDs with good crystallinity and thermal stability was rapidly synthesized by a simple supersaturation crystallization method at room temperature, which opened up a new way to improve the stability of PQDs and explore other non-toxic metal elements to replace Pb2+.

Revealing localized excitons in WSe2/β-Ga2O3

We have investigated the optical and magneto-optical properties of monolayer (ML) WSe2 on flakes of β-Ga2O3 under high magnetic fields. Remarkably, sharp emission peaks were observed and associated with localized excitons related to point defects. A detailed study of low-temperature photoluminescence (PL) and magneto-PL under high perpendicular magnetic field up to 9 T was carried out. Several sharp emission peaks have shown valley g-factors values close to −4, which is an unusual result for localized excitons in WSe2. Furthermore, some PL peaks have shown higher g-factor values of ≈−7 and ≈−12, which were associated with the hybridization of strain localized dark excitons and defects. The reported results suggest that β-Ga2O3 is, indeed, a promising dielectric substrate for ML WSe2 and also to explore fundamental physics in view of possible applications in quantum information technology.

Luminescent manifestations of ytterbium ions in the crystal structure of silicate apatite

The manifestation of ytterbium ions in the microcrystals of the Sr2Y6.8YbSi6O26:Er0.2 solid solution with apatite structure was studied on the basis of low-temperature photoluminescence (PL) spectroscopy and spectral-kinetic measurement data. Intracenter down-conversion luminescence of Er3+ ions in the visible and IR ranges was detected. Up-conversion luminescence of Er3+ ions is observed upon IR excitation due to excitation of Yb3+ ions and subsequent energy transfer Yb3+ → Er3+. Overlapping bands at 412 and 430 nm with a Stokes shift of less than 0.3 eV are observed in the PL spectra at room temperature. These emission bands are assigned to the spin-allowed and spin-forbidden 4f135d → 4f14 transitions from the low-spin and high-spin exciting states of Yb2+ ion, respectively. The PL decay kinetics for transitions from the low-spin states is characterized by a dominant component τ = 0.39 ns. An alternative model of Yb3+ luminescence center associated with a charge transfer band does not explain the data of low-temperature (5K) PL spectroscopy. At T = 5 K, a new wide emission band with a maximum at 696 nm and a Stokes shift of 1.1 eV appears in the PL spectrum. Two options of this PL band nature are considered. The first is the luminescence of defects having a vacancy nature. The second possible option is the manifestation of anomalous luminescence of Yb2+ ions, which occupy a different crystallographic position in the apatite crystal structure.

Low-temperature photoluminescence characteristic of Tm-doped Ga2O3 films for light emitting diodes application

Tm-doped Ga2O3 films hold significant promise for application in light-emitting diodes (LEDs). A comprehensive understanding of their photoluminescence properties is pivotal for unlocking their full potential. In this work, we present findings on the photoluminescence (PL) spectra of Tm-doped Ga2O3 films, elucidating variations at different measurement temperatures and excitation energies utilizing synchrotron radiation light. The intensity of ultraviolet light (UVL1 and UVL2) exhibits a temperature dependence and its activation energy illustrates an ionization energy of shallow donor and migration through tunneling of self-trapped holes to triply ionized Ga vacancy (VGa) centers forming doubly ionized VGa acceptors. Additionally, the excitation energy-dependent PL spectra provide insights into the excitation mechanism of Tm ions, indicating a most likely through defects in the Ga2O3 host.

Role of carbon in n-type bulk GaN crystals

In this work co-doping with silicon and carbon in gallium nitride grown by halide vapor phase epitaxy was performed. Native seeds of high structural quality with bowing radii of (0001) crystallographic planes higher than 15 m and threading dislocation density on the order of 5 × 104 cm−3 were used. The crystallized material was examined in terms of structural, optical, and electrical properties. For this purpose different characterization methods: X-ray diffraction, Raman spectroscopy, low-temperature photoluminescence, and Hall measurements, were applied. The physical properties of samples doped only with silicon and co-doped with carbon were analyzed and compared. However, during the crystallization process, due to high amount of Si and C, clusters of silicon carbide were unintentionally formed. The formation of these SiC clusters had an impact on the properties of the GaN crystals that were being studied. The research provides an initial insight into the complex studies of co-doping gallium nitride crystals. The results of this paper give us groundwork for more in-depth exploration of this topic.

Strain and optical characteristics analyses of three-dimentional self-ordered multilayered SiGe nanodots by photoluminescence and Raman spectroscopy

The strain state, optical properties, and band structure of the self-ordered multilayered silicon-germanium (SiGe) nanodots, which are staggered and dot-on-dot alignment and embedded by Si spacer, were evaluated by Raman spectroscopy and low-temperature photoluminescence (PL). These results suggest that the compressive strain applied to the staggered nanodots is smaller than that of the dot-on-dot nanodots, which contributes to the shrinking of the bandgap of the staggered nanodots. Strong PL intensity was observed from the nanodots compared to the single crystalline bulk SiGe due to the carrier confinement and high crystal quality of the nanodots. The stack-controlled nanodots showed a redshift of the PL peaks compared to the bulk SiGe and the effect of strain induced in SiGe nanodots might not be enough to explain this phenomenon. The cause of the redshift was clarified by considering the hetero band structure of the nanodots and the tensile strained spacer.

Chemical tuning of photo- and persistent luminescence of Cr3+-activated β-Ga2O3 by alloying with Al2O3 and In2O3

An effect of alloying of the monoclinic β-Ga2O3 with Al2O3 and In2O3 on the photoluminescent, thermoluminescent and persistent luminescent properties of Cr3+ ions has been comprehensively investigated. For this purpose, various series of Cr3+ and Ca2+ co-doped microcrystalline phosphors were synthesized by the solution combustion method, including pseudobinary compounds like (Ga-Al)2O3 with up to 20 % Al and (Ga-In)2O3 with up to 50 % In as well as pseudoternary compounds (Ga-Al-In)2O3 with balanced proportion of Al, Ga and In. The phase composition and crystal structure of the obtained materials were examined by X-ray powder diffraction technique. Detailed luminescence studies were conducted for the (Ga-Al)2O3 and (Ga-In)2O3 compounds which exhibited a single-phase monoclinic structure. Low-temperature and time-resolved photoluminescence investigations of the Cr-doped pseudobinary compounds unveiled several types of Cr3+ centres, attributed to the Al-, Ga- and In-centred octahedra in the studied alloys. The obtained results underscore the benefit of bandgap engineering through alteration in the host lattice chemical composition for efficient tuning of the thermoluminescent and persistent luminescent properties of the near-infrared-emitting β-Ga2O3:Cr based phosphors. Furthermore, it was demonstrated that modification of the chemical composition of the host lattice also adjusts the thermometric performance of the studied phosphors. Indeed, the specific sensitivity of the β-Ga2O3:Cr3+ decay time luminescence thermometer showed nearly twofold enhancement when the host lattice was alloyed with 30 % of In2O3.

Characterization of nanowire light-emitting diodes with InP/InAsP heterostructures emitting in telecom band

We report the growth and characterization of InP/InAsP/InP nanowires (NWs) and NW LEDs (NW-LEDs), which emit light at telecom wavelengths. InP-based NWs were grown by selective-area metal-organic vapor-phase epitaxy, and a thin InAsP layer was embedded in the NWs. The NW exhibited emission lines in their low-temperature photoluminescence spectra, suggesting the formation of quantum dots (QDs) in the NW. NW-LED operation was demonstrated at both room and low temperatures in the telecom band, but it was found that the emission wavelength range and blueshift behavior induced by current injection differed considerably between room and low temperatures. Our results suggest that an efficient path for carrier injection into the active InAsP layer should be explored for NW-QD-based single-photon sources operating via current-injection.

Broadband NIR luminescence of Cr3+-doped Mg4Nb2O9 phosphors toward LED light source applications for NIR spectrometry

Abstract Herein, we report the photoluminescence (PL) properties of Cr3+-doped Mg4Nb2O9 phosphors for applications in NIR phosphor-converted LEDs. Trigonal Mg4Nb2O9 crystals with Cr3+ substitution at three sites were synthesized as the main phase using a solid-state reaction. X-ray photoelectron spectrometry and diffuse reflectance spectroscopy indicated that only trivalent chromium ions were present in the samples. Broadband NIR emission of Cr3+ suitable for combination with Si photodetectors was confirmed at approximately 850 nm. The maximum PL quantum yield (PLQY) was 0.62, and concentration quenching explained the Cr concentration dependence of the PLQY and PL decay time. Low-temperature PL measurements suggested that the PL spectrum comprised three distinct emission bands. The results of the phonon line simulation, low-temperature PL excitation measurements, and crystal-field parameter estimation clarified the correlation between these emission bands and the Cr3+ substitution sites.

Improved performance of kesterite Cu2ZnSn(S,Se)4 thin film solar cells by Ag/Ge co-doping

Cation doping is an important approach to improve the performance of kesterite Cu2ZnSn(S,Se)4 (CZTSSe) thin film solar cells. Since different cation dopant has different effects on the defects and crystallization of CZTSSe absorber, it is expected to achieve better device performance via the synergistic effects of double cation co-doping compared with the single cation doping. Herein, we investigated the effects of Ag/Ge co-doping on CZTSSe solar cells by doping Ge in an already optimized Ag-alloyed CZTSSe (ACZTSSe). It is found that incorporating a small amount of Ge can further improve the crystallinity and minority carrier lifetime of ACZTSSe. The low-temperature photoluminescence results reveal that the Ge doping primarily suppressed the SnZn defects in ACZTSSe, thereby further boosting the device performance. However, higher Ge doping concentration can lead to a discontinuous surface morphology, which is believed to be related with the relatively low melting temperature and double-layered structure of ACZTSSe absorber. The deteriorated surface morphology results in photocurrent loss in the near-infrared region and decreased fill factor. As the Ge doping ratio increases, there is a balance between the defects and morphology. A champion power conversion efficiency (PCE), 11.4%, was achieved for the Ag/Ge co-doped CZTSSe solar cells at Ge substitution rate of 3%. Compared with the single Ag doping, the average PCE was further promoted by 0.5% due to Ag/Ge co-doping.

Strong Exciton-Phonon Coupling as a Fingerprint of Magnetic Ordering in van der Waals Layered CrSBr.

The layered, air-stable van der Waals antiferromagnetic compound CrSBr exhibits pronounced coupling among its optical, electronic, and magnetic properties. As an example, exciton dynamics can be significantly influenced by lattice vibrations through exciton-phonon coupling. Using low-temperature photoluminescence spectroscopy, we demonstrate the effective coupling between excitons and phonons in nanometer-thick CrSBr. By careful analysis, we identify that the satellite peaks predominantly arise from the interaction between the exciton and an optical phonon with a frequency of 118 cm-1 (∼14.6 meV) due to the out-of-plane vibration of Br atoms. Power-dependent and temperature-dependent photoluminescence measurements support exciton-phonon coupling and indicate a coupling between magnetic and optical properties, suggesting the possibility of carrier localization in the material. The presence of strong coupling between the exciton and the lattice may have important implications for the design of light-matter interactions in magnetic semiconductors and provide insights into the exciton dynamics in CrSBr. This highlights the potential for exploiting exciton-phonon coupling to control the optical properties of layered antiferromagnetic materials.

Bridgman-Grown (Cd,Mn)Te and (Cd,Mn)(Te,Se): A Comparison of Suitability for X and Gamma Detectors.

This study explores the suitability of (Cd,Mn)Te and (Cd,Mn)(Te,Se) as room-temperature X-ray and gamma-ray detector materials, grown using the Bridgman method. The investigation compares their crystal structure, mechanical and optical properties, and radiation detection capabilities. Both crystals can yield large-area single crystal samples measuring approximately 30 × 30 mm2. In low-temperature photoluminescence analysis, both materials showed defect states, and annealing in cadmium vapors effectively eliminated donor-acceptor pair luminescence in (Cd,Mn)Te but not in (Cd,Mn)(Te,Se). Moreover, harder (Cd,Mn)(Te,Se) exhibited a higher etch pit density compared to softer (Cd,Mn)Te. X-ray diffraction examination revealed uniform lattice constant distribution in both compounds, with variations at a part per million level. (Cd,Mn)Te crystals demonstrated excellent single crystal properties with narrower omega scan widths, while (Cd,Mn)(Te,Se) exhibited a high contribution of block-like structures with significantly larger misorientation angles. Spectroscopic evaluations revealed better performance of a pixelated (Cd,Mn)Te detector, in comparison to (Cd,Mn)(Te,Se), achieving a mean full width at half maximum of 14% for the 122 keV gamma peak of Co-57. The reduced performance of the (Cd,Mn)(Te,Se) detector may be attributed to deep trap-related luminescence or block-like structures with larger misorientation angles. In conclusion, Bridgman-grown (Cd,Mn)Te emerges as a more promising material for X-ray and gamma-ray detectors when compared to (Cd,Mn)(Te,Se).

Luminescence spectrum of cadmium chalcogenide photovoltaic film structures and their power enhancement

A technology has been developed for producing photovoltaic film structures of CdTe, CdTe:In, CdTe/CdS by thermal vacuum deposition, which allows increasing their operating power. An analysis of their low- temperature photoluminescence spectra shows a significant increase in their spectral sensitivity. It has been experimentally shown that there is a clear correlation between the anomalous photovoltaic (APV) properties and the shape of the intrinsic photoluminescence band of obliquely deposited CdTe films. The photoluminescence spectrum of a polycrystalline CdTe film with APV property is qualitatively different from the spectra of a single crystal, large-block polycrystal and single microcrystal. The main contribution to the photoluminescence of the film comes from radiative recombination of free carriers (A-line with half-width ΔEA≈14.2±0.1 meV) and edge luminescence with a wide doublet structure (B- and C - lines with half- widths 18.5±0.1 meV and 32.2±0.1 meV). When doped with In impurities and as a result of heat treatment, the emission spectrum is greatly transformed in accordance with the change in the photoelectric properties of the film. In the photoluminescence spectrum of a CdTe layer in a CdTe/CdS heterostructure grown under identical technological conditions as a CdTe monolayer, an additional broad spectral line appears due to the presence of a heterointerface, the superhot region disappears, and the A-emission line narrows somewhat (ΔEA≈11.2±0.1 meV), which significantly differ the studied film structures from the known CdS/CdTe heterosystems of other authors. The proposed method for analyzing low-temperature photoluminescence spectra makes it possible to purposefully control the technology for manufacturing photovoltaic film structures. The results obtained are of interest for film optoelectronics and solar cell manufacturing.

Refined structural studies on the fluorite-related polymorphs of sol-gel undoped and Eu3+-doped yttrium tantalates.

Compounds with the general formula RE3MO7 (RE = rare earth ions; M = Ta, Nb, Sb, Ru, Ir, Os, Re, etc.), crystallize as a fluorite-related structure, forming polymorphs with different space groups. The space group strongly depends on the RE3+ and M5+ ionic radii and processing conditions. Structural characterization is well-established for the lanthanide series, but literature studies have divergent views about how to attribute yttrium tantalate (Y3TaO7) space groups-some authors have described the Y3TaO7 structure as orthorhombic and belonging to space group C2221 or Ccmm, whereas others have assigned a cubic Fm3̄m structure to it. Here, we have characterized the structure of undoped and Eu3+-doped Y3TaO7 (0.1 to 50 mol% of Eu3+) samples synthesized by the sol-gel method that crystallized as a cubic disordered fluorite-type structure, space group Fm3̄m. Their powder X-ray diffraction measurements, Rietveld analyzes and Raman spectra were used as a conclusive technique of the structural properties. We have also investigated whether a secondary phase (M'-YTaO4) emerged in the samples and compared the phase composition of each sample to their Raman spectra. Low-temperature photoluminescence measurements (∼15 K) using Eu3+ as a structural probe helped us analyze the inhomogeneous broadening observed in the emission spectra. These measurements can be used as an important tool to attribute the crystalline phases of rare earth tantalates and niobates.

Preparation and characterization of SbSeI thin films

Metal chalcohalides are promising candidates for next-generation technologies that include energy conversion, information storage, and quantum computing. Among them, antimony selenoiodide (SbSeI) has received rising interest for different optoelectronic devices, including photovoltaics, due to its bandgap energy, strong optical absorption, stability, and earth abundant, low-cost, and low toxicity constituents. In this work, SbSeI thin films were prepared through a two-step process. At first, antimony selenide (Sb2Se3) thin films were deposited at 300 °C (Sb2Se3-300) and at room temperature (Sb2Se3-RT) onto molybdenum covered soda-lime glass substrates by a magnetron sputtering method. The formation of SbSeI thin films was performed by isothermally annealing the as-deposited Sb2Se3 thin films in sealed quartz ampoules in the atmosphere of antimony iodide (SbI3) with the presence of 100 Torr of argon pressure. The influence of the annealing temperature and time during the iodization of different types of substrates on the morphology and composition of SbSeI thin films was investigated. The well-oriented and dense single-phase SbSeI thin films with stoichiometric composition and single-crystal micro-columnar structures were achieved by annealing Sb2Se3-RT in SbI3 atmosphere at 250 °C for 5 min under 100 Torr of Ar pressure. The room temperature photoluminescence (RT-PL) of SbSeI exhibited a broad asymmetric PL band with a maximum at 1.67 eV. The low-temperature (T = 8 K) PL study of SbSeI showed a broad and asymmetric PL band at 1.4 eV, being quite distant from the bandgap. This PL band at 1.4 eV with obtained small thermal quenching activation energy of 12.7 meV is proposed to originate from the deep donor-deep acceptor pair (DD-DA) recombination.

A novel Sm2+ doped broadband far-red BaAl2Si3O4N4: Sm2+ phosphor for plant lighting applications

Far-red light plays a crucial role in the field of plant lighting. Herein, a novel far-red phosphor BaAl2Si3O4N4: Sm2+, which can be effectively excited by blue light, was successfully prepared by high-temperature solid-state reaction. The PL spectrum show a broadband emission range from 600 nm to 950 nm (FWHM = 120 nm), which is well matched with the absorption of PFR in plant. In BaAl2Si3O4N4: Sm2+, the Ba2+ are coordinated with three N and six O atoms. When the rare earth ion of Sm2+ was doped into the host lattice, Ba2+ was partially replaced by Sm2+. The low temperature PL spectra at 8–80 K were studied in detail. It was found that the PL spectra at low temperature were composed of some sharp lines and broadband superposition, which corresponding to the 5D0-7FJ (J = 0–4) energy level transition of Sm2+. It is shown that the broadband emission of the phosphor was caused by the broadening of the 4f55 d1 energy level due to the strong crystal field effect. The thermal stability analysis showed that the luminescence intensity of BaAl2Si3O4N4: Sm2+ at 150 °C still maintains 62.7 % of that at room temperature, showing excellent thermal stability. All results indicate that BaAl2Si3O4N4: Sm2+ phosphor has important potential applications in the field of plant lighting.