Optical Applications Research Articles

Programmable in-situ co-assembly of organic multi-block nanowires for cascade optical waveguides.

Organic heterostructures (OHs) with multi-segments exhibit special optoelectronic properties compared with monomeric structures. Nevertheless, the synthesis of multi-block heterostructures remains challenging due to compatibility issues between segment parts, which restricts their application in optical waveguides and integrated optics. Herein, we demonstrate programmable in-situ co-assembly engineering, combining multi-step spontaneous self-assembly processes to promote the synthesis of multi-block heterostructures with a rational arrangement of three or more segments. The rational design of segments enables exciton manipulation and ensures optical waveguides and proper output among the multi-segment OHs. This work enables the controllable growth of segments within multi-block OHs, providing a pathway to construct complex OHs for the rational development of future optical applications.

A comparative study of PMMA/PEG polymer nanocomposites doped with different oxides nanoparticles for potential optoelectronic applications

PMMA/PEG and PMMA/PEG doped with SiO2, TiO2, and Al2O3 were fabricated using the solution-casting technique. The composites were characterized by X-ray diffraction and scanning electron microscopy (FE-SEM), which revealed that the amorphous nature of PMMA/PEG blend doped with Al2O3 was hindered by the crystalline nature of those doped with SiO2 and TiO2. The absorption of PMMA/PEG blend doped with Al2O3 is higher, band gap energies were decreased from 4.90 eV for PMMA/PEG blend to 4.03 eV, 3.09 eV, and 2.09 eV for SiO2, TiO2, and Al2O3 doped PMMA/PEG blend, respectively. The dielectric constant, ε′ has a high value (2 × 104) for samples PMMA/PEG and SiO2/PMMA/PEG. While dielectric loss ε″\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left( {\\varepsilon ^{{\\prime \\prime }} } \\right)$$\\end{document}-values decreased to < 100 for TiO2/PMMA/PEG and Al2O3/PMMA/PEG. Further, the fabricated composite SiO2/PMMA/PEG led to improvement the optical and dielectric properties compared with PMMA/PEG for optoelectronic such as manufacturing of optical fiber cables application. The results show TiO2/PMMA/PEG and Al2O3/PMMA/PEG are multifunctional can be used as low-permittivity nanodielectric and substrates to design the next generation of flexible electronic devices.

Non‐Hermitian Skin Effect in Non‐Hermitian Optical Systems

AbstractThe development of non‐Hermitian (NH) physics in nonconservative systems has led to various interesting wave phenomena, including the emergence of the non‐Hermitian skin effect (NHSE). NHSE is a topological effect caused by the nontrivial winding number of the energy spectrum, which results in many bulk eigenmodes localized on low‐dimensional boundaries under open boundary conditions. Although this phenomenon is striking, the flexible and dynamic tuning of NHSE has not been reviewed in optics systems. As an ideal NH platform, an optical system can introduce artificially constructed gains and losses and flexibly design optical structures to control the transmission and regulation of light. This exploration based on NH optical systems deepens the understanding of NHSE and facilitates technological breakthroughs in high‐energy directional localized optics applications. In this review, the focus is on the latest progress and applications of NHSE in NH optical systems, including the basic theory and local property modulation methods. Finally, possible future research directions for NHSE based on NH optical systems are discussed.

Hybrid metal halide family with color-time-dual-resolved phosphorescence for multiplexed information security applications

Luminescent materials with engineered optical properties play an important role in anti-counterfeiting and information security technology. However, conventional luminescent coding is limited by fluorescence color or intensity, and high-level multi-dimensional luminescent encryption technology remains a critically challenging goal in different scenarios. To improve the encoding capacity, we present an optical multiplexing concept by synchronously manipulating the emission color and decay lifetimes of room-temperature phosphorescence materials at molecular level. Herein, we devise a family of zero-dimensional (0D) hybrid metal halides by combining organic phosphonium cations and metal halide tetrahedral anions as independent luminescent centers, which display blue phosphorescence and green persistent afterglow with the highest quantum yields of 39.9 % and 57.3 %, respectively. Significantly, the luminescence lifetime can be fine-tuned in the range of 0.0968–0.5046 μs and 33.46–125.61 ms as temporary time coding through precisely controlling the heavy atomic effect and inter-molecular interactions. As a consequence, synchronous blue phosphorescence and green afterglow are integrated into one 0D halide platform with adjustable emission lifetime acting as color- and time-resolved dual RTP materials, which realize the multiple applications in high-level anti-counterfeiting and information storage. The color-lifetime-dual-resolved encoding ability greatly broadens the scope of luminescent halide materials for optical multiplexing applications.

Optical response of Zr[formula omitted]CO[formula omitted]/MoS[formula omitted] van der Waals heterostructures calculated using first-principles calculations

In the field of material science, the search for a material with an optimal bandgap of approximately 1.40 eV that can act as an efficient photocatalyst for water splitting using solar spectrum irradiation is a noble mission. In this article, we explore the structural, electronic structure, optical and photocatalytic properties of Zr2CO2/MoS2 vdW heterostructures. Our results demonstrates that the Zr2CO2/MoS2 vdW heterostructure can be reliably synthesized. This is due to a minimal lattice mismatch of less than 3%, a negative adhesion energy of -4.23 meV/Å 2, and inherent dynamic stability. The electronic band structure calculations indicate that the Zr2CO2/MoS2 vdW heterostructure is an indirect bandgap semiconductor. We found that the conduction band minimum (CBM) and valance band maximum (VBM) of the heterostructure are located in different monolayers. Furthermore, under −2% biaxial strain a transition from type-I to type-II (staggered) band alignment occurred. Stacking 2D MoS2 on the Zr2CO2 monolayer results in a vdW heterostructure, and as a result, the HSE calculated bandgap of the Zr2CO2/MoS2 vdW heterostructure in most stable configuration lying in the ideal range for photocatalytic applications. We also studied the heterostructure’s optical properties to understand its response to incident photons with energies up to 14 eV. Based on our findings, Zr2CO2/MoS2 heterostructures are desirable for optoelectronic device applications operated in visible range. Our research offers fresh recommendations for developing novel, highly effective photocatalytic compounds with numerous optical device applications.

Flow and Batch Minute-Made Synthesis of Ce-UVM-7 Using Microwave-Assisted Reaction: Scaling-Up, Optical and Catalytic Applications, and Impact Assessment

Flow and Batch Minute-Made Synthesis of Ce-UVM-7 Using Microwave-Assisted Reaction: Scaling-Up, Optical and Catalytic Applications, and Impact Assessment

Development of barium borosilicate glasses reinforced with CdO for potential use in optical and γ-ray protection applications

Development of barium borosilicate glasses reinforced with CdO for potential use in optical and γ-ray protection applications

In Situ Formation of SnSe2/SnSe Vertical Heterostructures toward Polarization Selectable Band Alignments.

2D van der Waals (vdW) layered semiconductor vertical heterostructures with controllable band alignment are highly desired for nanodevice applications including photodetection and photovoltaics. However, current 2D vdW heterostructures are mainly obtained via mechanical exfoliation and stacking process, intrinsically limiting the yield and reproducibility, hardly achieving large-area with specific orientation. Here, large-area vdW-epitaxial SnSe2/SnSe heterostructures are obtained by annealing layered SnSe. These in situ Raman analyses reveal the optimized annealing conditions for the phase transition of SnSe to SnSe2. The spherical aberration-corrected transmission electron microscopy investigations demonstrate that layered SnSe2 epitaxially forms on SnSe surface with atomically sharp interface and specific orientation. Optical characterizations and theoretical calculations reveal valley polarization of the heterostructures that originate from SnSe, suggesting a naturally adjustable band alignment between type-II and type-III, only relying on the polarization angle of incident lights. This work not only offers a unique and accessible approach to obtaining large-area SnSe2/SnSe heterostructures with new insight into the formation mechanism of vdW heterostructures, but also opens the intriguing optical applications based on valleytronic nanoheterostructures.

The Performance of The Opening Ceremony of the 2022 Beijing Winter Olympics

This study adopts research methods such as literature review and interview to analyze the performance of the opening ceremony of the 2022 Beijing Winter Olympics. The study focuses on the Olympic concept, duration, national culture, AI use, optical application, stage design, fireworks performance, venue selection, and the relationship with technological development. give the result as follows1. Simplicity, beauty, modernity. Showcasing three themes, namely China's pursuit and longing for world peace, "Faster, Higher, Stronger, and more united", and "Together towards the future".2. The blessing of technology is more important than any previous Olympic opening ceremony performance. Human screen dance technology, holographic projection technology, AI technology empowerment, 3D lighting stage technology, double-sided screen technology, laser engraving technology, and irregular screen technology will be the main means of empowering the Olympic opening ceremony performance.3.The color scheme of the opening ceremony of the Beijing Winter Olympics is mainly cold, which blends harmoniously with the emphasis on ice and snow in the Winter Olympics.4.The development and utilization of ethnic elements in the opening ceremony performance of this Winter Olympics are reasonable and appropriate, mainly including Chinese paintings, Chinese totems, Chinese stories, Chinese proverbs, Chinese characters, Chinese clothing, etc.5.The selection of the performance venue for the opening ceremony at the National Stadium of China seems somewhat conservative.6.Reduced the fixed construction stage and replaced it with a variable and mobile stage. Technological stage. The use of LED screens makes the performance more diverse.7.The ignition ceremony highlights the ice and snow of the Winter Olympics, showcases the subtle fire in a low-key manner, highlights the theme, and also embodies the concept of low-carbon environmental protection8.The opening ceremony performance of this Winter Olympics focuses more on sports performances, downplaying artistic performances and highlighting sports characteristics. Performed by ordinary citizens, primary, secondary, and high school students, as well as young people from all over the world, emphasizing the need for everyone to come together.

Virtual reality for understanding artificial-intelligence-driven scientific discovery with an application in quantum optics

Virtual reality for understanding artificial-intelligence-driven scientific discovery with an application in quantum optics

Multimodal anti-counterfeiting and optical storage application based on luminescence reversible modification and color change of photochromic phosphor

Reversible upconversion luminescence (RUCL) modification based on photochromism has received considerable interest due to its potential applications in optical storage and invisible optical anti-counterfeiting. Herein, white β-Ba2ScAlO5: Yb3+, Er3+ (β-BSAO-YE) phosphor was irradiated with 254 nm light, which caused the phosphor to turn blue due to the increase of oxygen vacancy. The blue β-BSAO-YE phosphor returns to its original color upon stimulation with 808 nm laser light or 125 °C, exhibiting a double photo-induced reversible photochromic change. The green and red upconversion luminescence (UCL) of the β-BSAO-YE were reversibly modified according to their photochromic properties. The UCL modification changes the luminescence color of the pattern, indicating that β-BSAO-YE phosphor is an ideal compound anti-counterfeit agent. The light information recorded on the β-BSAO-YE binary photochromic dot matrix can be read under ultraviolet (UV) and near-infrared (NIR) excitation, demonstrating the potential application of β-BSAO-YE phosphors as optical data storage media. In addition, the cyclic experiment showed good photochromic and UCL modulation repeatability. The new luminescent β-BSAO-YE not only proposes a new way to exploring upconversion red light materials, but also provides new materials for optical storage, optical information and optical anti-counterfeiting.

Free-volume analysis of the structural and dielectric properties of PMMA/TeO2 composites via positron annihilation lifetime spectroscopy

PMMA (Poly methyl methacrylate) composites have promising potential for applications in optics and dielectric energy storage. To investigate the effects of TeO2 contents in PMMA in this respect, we studied their composites on light absorption in the UVvisible range, structural analysis via X-ray diffraction, dielectric characteristics, and free volume behavior. We added up to approximately 7 % of the weight concentration of the TeO2 micropowder to the PMMA matrix for effective dispersion because of the limitations of ultrasonic agitation. The XRD data demonstrate a widening of the peaks with a filler content of up to 4.8 % and agglomeration at 7 %, indicating TeO2 particle contact. An increase in absorbance was observed in the UVvisible spectrum of the PMMA/TeO2 composites with increasing TeO2 content up to 4.8 %. The dielectric constants exhibit a positive correlation with higher quantities of TeO2, and the polarization mechanism is interpreted by interface polarization and free volume. The free volume measured by positron annihilation lifetime spectroscopy (PALS) increases to 4.8 % but decreases to 7 %. The effect of the free volume within the matrix on the polarization distribution of TeO2 influenced the dielectric constant and the loss factor, which increased to 4.8 % and then decreased to 7 % due to agglomeration.

Manipulation and applications of ultrafast all-optical switching based on transient absorption and dispersion in KTN crystals.

Potassium tantalate niobate (KTN) represents a noteworthy category of optical crystals known for their superior nonlinear optical properties. In this study, we conducted measurements of femtosecond time-resolved transient absorption (TA) spectra in KTa0.57Nb0.43O3 crystals. Notably, a rapid and pronounced "plateau" phase, ∼1.5 ps in duration, was detected at the onset of the TA kinetics and succeeded by two distinct decay components, exhibiting lifetimes of ∼140 ps and over 10 ns, respectively. We attribute these observations to a decay process involving two-photon absorption, dispersion characteristics, and excited state absorption. Based on this unique TA characteristic of KTN crystals, an all-optical switching strategy was proposed and utilized to measure the ultrafast lasing dynamics of single-crystal CH3NH3PbBr3 nanowires. This polarization-independent TA gate approach offers an adjustable gate width combining ps and ns time scales and introduces a versatile tool for advanced optical applications.

Cascaded multi-phonon stimulated Raman scattering near second-harmonic generation in a thin-film lithium niobate microdisk.

High-quality microresonators can greatly enhance light-matter interactions and are excellent platforms for studying nonlinear optics. Wavelength conversion through nonlinear processes is the key to many applications of integrated optics. The stimulated Raman scattering (SRS) process can extend the emission wavelength of a laser source to a wider range. Lithium niobate (LN), as a Raman active crystalline material, has remarkable potential for wavelength conversion. Here, we demonstrate the generation of cascaded multi-phonon Raman signals near the second-harmonic generation (SHG) peak in an X-cut thin-film lithium niobate (TFLN) microdisk. Fine tuning of the specific cascaded Raman spectral lines has also been made by changing the pump wavelength. Raman lines can reach a wavelength up to about 80 nm away from the SHG signal. We realize the SFG process associated with Raman signals in the visible range as well. Our work extends the use of WGM microresonators as effective optical upconversion wavelength converters in nonlinear optical applications.

Mo4/3B2T2/Co3O4 vdW heterostructure as saturable absorber for ultrafast pulse generation

VdW heterostructure have garnered significant interest in ultrafast laser generation because of their attractive saturable absorption properties, holding promise for applications in optics, medicine, and optoelectronics. In this study, the saturable absorption of Mo4/3B2T2/Co3O4 vdW is investigated for the first time. Mo4/3B2T2/Co3O4 vdW SA is successfully applied to passively mode-locked Er-doped fiber lasers. Due to the excellent saturable absorption properties of Mo4/3B2T2/Co3O4 vdW SA, stable mode-locked fiber lasers can be realized in the same cavity, including fundamentally conventional soliton, bound soliton, and harmonic soliton. Among them, the conventional soliton operates at a repetition rate of 11.16 MHz with a high SNR of 56.26 dB. Bound soliton is observed with a soliton pulse separation of 5.26 ps. Furthermore, 3rd-, 5th-, 8th-, 10th-, 12th-, 15th-, and 17th-order harmonic solitons are observed, corresponding to repetition rates of 33.48 MHz, 55.8 MHz, 89.28 MHz, 111.6 MHz, 133.92 MHz, 167.4 MHz and 189.72 MHz, respectively. For vdW heterostructure, the saturable absorption properties are strongly modulated by the interlayer coupling, which may be introduced by the Fermi level recombination and photogenerated carrier migration between the heterostructure. We established a model to understand the saturable absorption properties of the Mo4/3B2T2/Co3O4, which suggests the enhancements of the saturable absorption are attributed to the carrier migration between Mo4/3B2T2 and Co3O4. The results indicate that Mo4/3B2T2/Co3O4 vdW heterostructure can be used as an excellent nonlinear optical material, which can be used as SA in ultrafast pulse generation.

A comparative spin orbit coupling DFT study of opto-electronic properties of [formula omitted] and [formula omitted] bulk crystal

Bi2Se3 and Bi2Te3 are the ideal candidate for spintronics and many other novel applications due to their strong opto-electronic properties. These materials are regarded as topological insulator as they portray band inversion which is considered to be a key signature of topology. Moreover, because of their superior opto-electronic qualities, Bi2Se3 and Bi2Te3 are intriguing in the realm of optical and electronic applications. This paper compares the optical and electronic characteristics of Bi2Te3 and Bi2Se3 in the framework of density functional theory taking PBE-GGA and mBJ-GGA as exchange correlation potential. The analysis of band structure and density of states (DOS) confirms the gapped nature without and with SOC calculation. The introduction of SOC gives the accurate result which matches with the experimental figure. Optical properties including reflectivity, absorption coefficient, energy loss function, refractive index, extinction coefficient, and optical conductivity are analyzed without and with SOC. We have also calculated birefringence, dichroism, and the optical skin depth which has not been reported yet for those compounds. The spectroscopic limited maximum efficiency (SLME), which theoretically determines the power conversion efficiency (PCE) of solar cells is also calculated. Based on the optical and electronic properties, possible uses of Bi2Se3 and Bi2Te3 are discussed without and with SOC effect.

Experience With an Optical Character Recognition Search Application for Review of Outside Medical Records

Experience With an Optical Character Recognition Search Application for Review of Outside Medical Records

(Invited) Defect Photoluminescence Generation in Boron Nitride Nanotubes by Chemical Functionalization Approaches

Boron nitride nanotubes (BNNTs) are structural analogues of carbon nanotubes (CNTs). They have nanocylindrical structures composed of rolled-up hexagonal boron nitride (h-BN) sheets. The BN framework consists of alternately connecting boron and nitrogen atoms with sp2 hybridization. Therein, a strong covalent bond with an ionic character is formed due to their electronegativity difference. Accordingly, BNNTs exhibit unique properties such as high mechanical strength, thermal stability, and a wide bandgap semiconducting feature [1]. The large bandgap (ca. 6 eV) is less dependent on tube diameters and chiralities, and optical absorption and emission for pristine tubes occur in deep UV regions (around 200 nm) based on the band edge transition. In typical BNNT samples, however, atomic vacancies in the BN framework are reported to provide longer wavelength photoluminescence (PL) in UV–vis regions [2].To date, chemical functionalization of single-walled CNTs (SWCNTs) have been developed to create luminescent defects emitting red-shifted and bright near-infrared PL [3-6]. In this study, we use the chemical functionalization method to produce luminescent defects in BNNTs [7].A reductive alkylation reaction for BNNTs was conducted using sodium naphthalenide and 1-bromohexane to synthesize hexylated BNNTs (h-BNNTs). In a PL spectrum of h-BNNTs, PL peaks appeared at 334 and 413 nm, which were not observed for unmodified BNNTs. X-ray photoelectron spectroscopy revealed that the hexyl group was covalently attached on the boron site of BNNTs, by which sp3 hybridized boron atoms were partly formed in the BN network as defects. The covalent attachment of the hexyl group was also confirmed by atomic-resolution transmission electron microscope observations. Chemical reaction conditions were found to be a key factor for the emission wavelength variations of the resultant defect PL. Therefore, it is revealed that the luminescent defect formation in BNNTs is achieved based on the chemical functionalization approach. The functionalized BNNTs would be applicable to advanced optical applications such as quantum light sources.[1] D. Golberg et al. ACS Nano,4, 2979 (2010). [2] L. Museur et al. J. Appl. Phys., 118, 084305 (2015). [3] T. Shiraki et al. Acc. Chem. Res., 53, 1846 (2020). [4] B. Gifford et al. Acc. Chem. Res., 53, 1791 (2020). [5] A. H. Brozena et al. Nat. Rev. Chem. 3, 375 (2019). [6] J. Zaumseil. Adv. Opt. Mater. 10, 2101576 (2022). [7] T. Shiraki et al. Chem. Lett. 52, 44 (2023). Figure 1

Nanoparticle/Cellulose-Based Surface Enhanced Raman Scattering Hybrid Sensors

Surface-Enhanced Raman Scattering (SERS) sensors are versatile biosensors for detecting very low concentrations of molecules. Their molecular and chemical sensitivity crucially depends on the tailoring of their nanostructure. These sensors rely on noble metal or oxide cluster layers, with their crystallinity and nanostructure carefully tuned to enable a maximum of plasmonic hot spots and enabling charge transfer. Typically, such sensors are in thin film geometry. In order to optimize their nanostructure and optical properties of the metal or oxide clusters, cellulose nanofibrils (CNFs) as template for nanoparticle-biopolymer hybrid materials are readily employed due to their high mechanical strength and ability to establish nanoporous, scalable thin films via spray deposition.[1] In order to characterize their nanostructure during synthesis of the hybrid nanoparticle-CNF material, grazing incidence X-ray scattering (GIXS) is ideally suited due to its ability to observe the nanostructural changes during farication and optimization of the sensor materials. The resulting nanostructure is then directly correlation to the sensor capability of the hybrid materials. As a first example, we use the catalytic properties of CNF during thermal decomposition of silver nitrate as precursor for fabrication of size-tuned silver clusters on CNF to tune their optical band-gap. The correlation between hot-spot size and silver nanoparticle size for optimizing the SERS sensitivity is elucidated using GIXS, showing for the first time the optimum hot spot size.[2] In order to facilitate an equal distribution of hot-spots, we make use of the three-dimensional nanoporous structure of the CNF thin films by adding shell-free silver nanoparticles in aqueous solution, again applying spray deposition.[3] The nanoporosity allows for reducing drastically agglomerations of silver nanoparticles, detrimental to hot-spots. At the same time, the spectral position of the plasmon resonance is tuned by the amount of CNF as structural matrix. As a final example we extend these results to novel semiconductor metal oxide nanomaterial (SMON)-based sensors.[4] Here, titanium oxide is deposited via atomic layer deposition (ALD) on the nanoporous CNF network, preserving its three-dimensional morphology. We optimize the nanostructure, crystallinity and rutile-to-anatase ratio in order to obtain superior sensitivity of the hybrid titania/CNF thin films as SMON SERS substrates. The improvement of SERS activity relies on the cooperative modulation of the CNF network and the crystalline states of the deposited titania. To summarize, we present new routes for SERS sensors based on plasmonic and charge transfer properties of hybrid materials by tailoring the hybrid nanostructure.[1] Brett, C. J.; Ohm, W.; Fricke, B.; Alexakis, A. E.; Laarmann, T.; Körstgens, V.; Müller-Buschbaum, P.; Söderberg, L. D.; Roth, S. V. Nanocellulose-Assisted Thermally Induced Growth of Silver Nanoparticles for Optical Applications. ACS Appl. Mater. Interfaces 2021, 13 (23), 27696–27704. https://doi.org/10.1021/acsami.1c07544.[2] Santoro, G.; Yu, S.; Schwartzkopf, M.; Zhang, P.; Koyiloth Vayalil, S.; Risch, J. F. H.; Rübhausen, M. A.; Hernández, M.; Domingo, C.; Roth, S. V. Silver Substrates for Surface Enhanced Raman Scattering: Correlation between Nanostructure and Raman Scattering Enhancement. Appl. Phys. Lett. 2014, 104 (24), 243107. https://doi.org/10.1063/1.4884423.[3] Chen, Q.; Brett, C. J.; Chumakov, A.; Gensch, M.; Schwartzkopf, M.; Körstgens, V.; Söderberg, L. D.; Plech, A.; Zhang, P.; Müller-Buschbaum, P.; Roth, S. V. Layer-by-Layer Spray-Coating of Cellulose Nanofibrils and Silver Nanoparticles for Hydrophilic Interfaces. ACS Appl. Nano Mater. 2021, 4 (1), 503–513. https://doi.org/10.1021/acsanm.0c02819.[4] Chen, Q.; Betker, M.; Harder, C.; Brett, C. J.; Schwartzkopf, M.; Ulrich, N. M.; Toimil‐Molares, M. E.; Trautmann, C.; Söderberg, L. D.; Weindl, C. L.; Körstgens, V.; Müller‐Buschbaum, P.; Ma, M.; Roth, S. V. Biopolymer‐Templated Deposition of Ordered and Polymorph Titanium Dioxide Thin Films for Improved Surface‐Enhanced Raman Scattering Sensitivity. Adv. Funct. Mater. 2022, 32 (6), 2108556. https://doi.org/10.1002/adfm.202108556.

Tailoring electronic and optical properties of Lutetium pyrosilicate (Lu2Si2O7) through Nd and Tb doping: Insights from DFT+U calculations

In this research paper, we investigate the electronic and optical properties of Lutetium pyrosilicate (Lu2Si2O7, LPS) by Nd and Tb doping using density functional theory (DFT) calculations within the framework of the WIEN2k code. The DFT + U method is employed to account for the strong correlation effects in the rare earth dopants. The analysis of the electronic properties reveals that the materials under investigation exhibit semiconductor behavior. The calculated spin up/dn energy band gaps for pristine, Nd & Tb doping Lu2Si2O7 are determined to be 4.610/4.660 eV, 4.635/5.162 eV, and 5.06/4.45 eV, respectively. Our results reveal that the doping of Nd and Tb impurities leads to the introduction of new electronic states within the band gap of Lu2Si2O7, resulting in a significant modification of the electronic and optical properties. Specifically, we find that the Tb-doped Lu2Si2O7 shows a wide band gap and enhanced optical absorption in the visible region, while the Nd-doped Lu2Si2O7 exhibits a broadened band gap and reduced optical absorption in the visible region. This study can provide a reference for future research and helps to extend the properties of Lu2Si2O7 by Nd and Tb materials into the optical applications.