SiGeC: Band gaps, band offsets, optical properties, and potential applications

Cu2S nanowire arrays with different morphologies were prepared by solid-gas reaction between Cu foil and mixture gas of H2S and O2. Their microstructures were observed with XRD, TEM, and the optical properties were measured by DRS, PL and Raman. The results showed that the nanowire were Cu2S single crystal with a thin layer CuxO (x=1, 2) over the surface. The optical properties of the Cu2S nanowire arrays are related to the diameter, length, and distribution density of nanowire arrays. The thinner is the nanowire’s diameter; the bigger is the absorption of the visible light, and the absorbance begun to descend within infrared band. The absorbance of nanowire arrays with bigger diameter to the infrared light was stronger than that with thinner diameter. The photoluminescence spectrum (PL) indicated that band gaps of Cu2S nanowire arrays also changed simultaneously with the nanowire arrays’ structure parameters. The research demonstrated the Cu2S nanowire arrays’ potential applications in the photovoltaic cell and solar-heat harvesting area.

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A New Type of Cuprous-Cysteamine Sensitizers: Synthesis, Optical Properties and Potential Applications

Materials Today Physics ◽

10.1016/j.mtphys.2021.100435 ◽

2021 ◽

pp. 100435

Author(s):

Yan Wang ◽

Noura Dawas Alkhaldi ◽

Nil Kanatha Pandey ◽

Lalit Chudal ◽

Lingyun Wang ◽

...

Keyword(s):

Optical Properties ◽

Potential Applications ◽

New Type

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Enhanced luminescence properties of Ca1+xSr2−xAl2O6:Eu3+ (0 ≤ x ≤ 1) red phosphors based on composition modulation

RSC Advances ◽

10.1039/d1ra01291f ◽

2021 ◽

Vol 11 (21) ◽

pp. 12981-12989

Author(s):

Biao Shen ◽

Jianghang Xu ◽

Qinan Mao ◽

Jiasong Zhong

Keyword(s):

Optical Properties ◽

Quantum Efficiency ◽

Luminescence Properties ◽

Composition Modulation ◽

Red Phosphors ◽

Potential Applications ◽

Enhanced Luminescence

A series of Ca1+xSr2−xAl2O6:Eu3+ (0 ≤ x ≤ 1) red-emitting phosphors with adjustable optical properties and excellent quantum efficiency was developed for potential applications in warm WLEDs.

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Changes in Optical Properties upon Dye–Clay Interaction: Experimental Evaluation and Applications

Nanomaterials ◽

10.3390/nano11010197 ◽

2021 ◽

Vol 11 (1) ◽

pp. 197

Author(s):

Giorgia Giovannini ◽

René M. Rossi ◽

Luciano F. Boesel

Keyword(s):

Optical Properties ◽

Hybrid Materials ◽

High Performance ◽

Fluorescent Properties ◽

Chemical Mechanisms ◽

Strong Electrostatic Interaction ◽

Potential Applications ◽

Photochemical Properties ◽

Physical And Chemical ◽

The Relationship

The development of hybrid materials with unique optical properties has been a challenge for the creation of high-performance composites. The improved photophysical and photochemical properties observed when fluorophores interact with clay minerals, as well as the accessibility and easy handling of such natural materials, make these nanocomposites attractive for designing novel optical hybrid materials. Here, we present a method of promoting this interaction by conjugating dyes with chitosan. The fluorescent properties of conjugated dye–montmorillonite (MMT) hybrids were similar to those of free dye–MMT hybrids. Moreover, we analyzed the relationship between the changes in optical properties of the dye interacting with clay and its structure and defined the physical and chemical mechanisms that take place upon dye–MMT interactions leading to the optical changes. Conjugation to chitosan additionally ensures stable adsorption on clay nanoplatelets due to the strong electrostatic interaction between chitosan and clay. This work thus provides a method to facilitate the design of solid-state hybrid nanomaterials relevant for potential applications in bioimaging, sensing and optical purposes.

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A Nanoscale Adventure with Silicon: Synthesis, Surface Chemistry, and other Surprises

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.242.383 ◽

2015 ◽

Vol 242 ◽

pp. 383-390

Author(s):

Md Hosnay Mobarok ◽

Tapas K. Purkait ◽

Jonathan G.C. Veinot

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Surface Chemistry ◽

Research Group ◽

Size Dependent ◽

Earth Abundant ◽

Potential Applications ◽

Si Quantum Dots

The preparation and surface chemistry Si quantum dots (SiQDs) are currently an intense focus of research because of their size dependent optical properties and many potential applications. SiQDs offer several advantages over other quantum dots; Si is earth abundant, non-toxic and biocompatible. This account briefly highlights recent advancements made by our research group related to the synthesis, functionalization, surface dependent optical properties and applications of SiQDs.

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Electronic Structure and Optical Properties of Co and Fe Doped ZnO

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.43.23 ◽

2016 ◽

Vol 43 ◽

pp. 23-28 ◽

Cited By ~ 1

Author(s):

Chun Ping Li ◽

Ge Gao ◽

Xin Chen

Keyword(s):

Density Functional Theory ◽

Optical Properties ◽

Electronic Structures ◽

Density Functional ◽

Band Gaps ◽

First Principle ◽

Functional Theory ◽

Doped Zno ◽

Pseudo Potential ◽

Co Doped

First-principle ultrasoft pseudo potential approach of the plane wave based on density functional theory (DFT) has been used for studying the electronic characterization and optical properties of ZnO and Fe, Co doped ZnO. The results show that the doping impurities change the lattice parameters a little, but bring more changes in the electronic structures. The band gaps are broadened by doping, and the Fermi level accesses to the conduction band which will lead the system to show the character of metallic properties. The dielectric function and absorption peaks are identified and the changes compared to pure ZnO are analyzed in detail.

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Structural, electrical and optical properties of Mg-doped CuAlO2 films by pulsed laser deposition

RSC Advances ◽

10.1039/c4ra06390b ◽

2014 ◽

Vol 4 (78) ◽

pp. 41294-41300 ◽

Cited By ~ 13

Author(s):

Y. S. Zou ◽

H. P. Wang ◽

S. L. Zhang ◽

D. Lou ◽

Y. H. Dong ◽

...

Keyword(s):

Optical Properties ◽

Pulsed Laser Deposition ◽

Pulsed Laser ◽

Band Gaps ◽

Laser Deposition ◽

Electrical And Optical Properties ◽

Optical Band Gaps ◽

P Type ◽

Enhanced Conductivity ◽

Mg Doped

P-type Mg doped CuAlO2 films with high crystallinity are prepared by pulsed laser deposition followed by annealing, and exhibit enhanced conductivity and tunable optical band gaps.

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Compositional Changes in the Infrared Optical Properties of Cr Doped CdZnTe Crystals

MRS Proceedings ◽

10.1557/proc-864-e4.19 ◽

2005 ◽

Vol 864 ◽

Author(s):

U. Hömmerich ◽

A.G. Bluiett ◽

EiEi Nyein ◽

S.B. Trivedi ◽

R.T. Shah

Keyword(s):

Optical Properties ◽

Ir Absorption ◽

Solid State Lasers ◽

Crystal Field Effect ◽

Spectral Shifts ◽

Zn Content ◽

Potential Applications ◽

Vertical Bridgman ◽

Compositional Changes ◽

Ir Emission

AbstractWe are currently investigating the infrared (IR) optical properties of Cr doped ternary cadmium chalcogenides for potential applications in solid-state lasers and passive optical Qswitches. In this paper, we present compositional changes in the IR optical properties of Cr doped Cd1-xZnxTe single crystals with x=0.05, 0.1, and 0.2. Undoped CdZnTe crystals were grown by vertical Bridgman technique. Cr doping of CdZnTe was achieved through either in-situ doping or through a thermal diffusion process. For comparison, Cr: CdTe and Cr: ZnTe crystals were also prepared. The optical properties of Cr2+ ions were strongly dependent on the host composition and spectral blue shifts were observed with increasing Zn content in Cr: CdZnTe. The IR absorption peak of Cr2+ ions shifted from ∼1910 nm for Cr: CdTe to ∼1815 nm for Cr: Cd0.8Zn0.2Te. Less pronounced blue shifts were observed for the IR emission from Cr: CdZnTe crystals. The spectral shifts can be explained by the decrease in bond-length when going from CdTe to CdZnTe leading to an increased crystal-field effect experienced by Cr2+ ions. A slight broadening of the absorption and emission was also observed in ternary Cr: CdZnTe compounds compared to Cr: CdTe, which suggests that Cr2+ ions were incorporated in multiple lattice sites in CdZnTe. Moreover, the Cr2+ emission dynamics revealed a slightly non-exponential decay behavior for Cr: CdZnTe crystals, whereas the decay time of Cr: CdTe was single-exponential.

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First principles study of structure, electronic and optical properties of Y3Fe5O12 in cubic and trigonal phases

Materials Science-Poland ◽

10.1515/msp-2015-0015 ◽

2015 ◽

Vol 33 (1) ◽

pp. 169-174 ◽

Cited By ~ 4

Author(s):

Shen Tao ◽

Hu Chao ◽

Dai Hailong ◽

Yang Wenlong ◽

Liu Hongchen ◽

...

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Energy Loss ◽

First Principles ◽

Structural Parameters ◽

Band Gaps ◽

First Principles Calculations ◽

Electronic And Optical Properties ◽

Direct Band ◽

Experimental Values

AbstractFirst principles calculations have been performed to investigate the structure, electronic and optical properties of Y3Fe5O12. Both the cubic and trigonal phases have been considered in our calculation. The calculated structural parameters are slightly larger than the experimental values. The band structures show that Y3Fe5O12 in cubic and trigonal phases have direct band gaps of 0.65 and 0.17 eV. The calculations of dielectric function, absorption, extinction coefficient, refractive index, energy loss function and reflectivity are presented.

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Tuning the electronic and optical properties of hexagonal boron-nitride nanosheet by inserting graphene quantum dots

Modern Physics Letters B ◽

10.1142/s0217984918500847 ◽

2018 ◽

Vol 32 (06) ◽

pp. 1850084 ◽

Cited By ~ 2

Author(s):

Yi-Min Ding ◽

Jun-Jie Shi ◽

Min Zhang ◽

Meng Wu ◽

Hui Wang ◽

...

Keyword(s):

Quantum Dots ◽

Optical Properties ◽

Boron Nitride ◽

Hexagonal Boron Nitride ◽

Graphene Quantum Dots ◽

Band Gaps ◽

Hybrid Structures ◽

Electronic And Optical Properties ◽

Boron Nitride Nanosheet ◽

Optoelectronic Nanodevices

It is difficult to integrate two-dimensional (2D) graphene and hexagonal boron-nitride (h-BN) in optoelectronic nanodevices, due to the semi-metal and insulator characteristic of graphene and h-BN, respectively. Using the state-of-the-art first-principles calculations based on many-body perturbation theory, we investigate the electronic and optical properties of h-BN nanosheet embedded with graphene dots. We find that C atom impurities doped in h-BN nanosheet tend to phase-separate into graphene quantum dots (QD), and BNC hybrid structure, i.e. a graphene dot within a h-BN background, can be formed. The band gaps of BNC hybrid structures have an inverse relationship with the size of graphene dot. The calculated optical band gaps for BNC structures vary from 4.71 eV to 3.77 eV, which are much smaller than that of h-BN nanosheet. Furthermore, the valence band maximum is located in C atoms bonded to B atoms and conduction band minimum is located in C atoms bonded to N atoms, which means the electron and hole wave functions are closely distributed around the graphene dot. The bound excitons, localized around the graphene dot, determine the optical spectra of the BNC hybrid structures, in which the exciton binding energies decrease with increase in the size of graphene dots. Our results provide an important theoretical basis for the design and development of BNC-based optoelectronic nanodevices.

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