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

2005 ◽  
Vol 864 ◽  
Author(s):  
U. Hömmerich ◽  
A.G. Bluiett ◽  
EiEi Nyein ◽  
S.B. Trivedi ◽  
R.T. Shah

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.

2021 ◽  
pp. 100435
Author(s):  
Yan Wang ◽  
Noura Dawas Alkhaldi ◽  
Nil Kanatha Pandey ◽  
Lalit Chudal ◽  
Lingyun Wang ◽  
...  

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12981-12989
Author(s):  
Biao Shen ◽  
Jianghang Xu ◽  
Qinan Mao ◽  
Jiasong Zhong

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.


Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 197
Author(s):  
Giorgia Giovannini ◽  
René M. Rossi ◽  
Luciano F. Boesel

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Shu-Ru Chung ◽  
Kuan-Wen Wang ◽  
Hong-Shuo Chen

We present a facile one-pot synthesis to prepare ternaryZnxCd1-xSe(x= 0.2, 0.5, 0.8, and 1) nanocrystals (NCs) with high emission quantum yield (QY, 45~89%). The effect of Zn content (x) ofZnxCd1-xSeNCs on their physical properties is investigated. The NCs have a particle size of 3.2 nm and face centered cubic structure. However, the actual compositions of the NCs are Zn0.03Cd0.97Se, Zn0.11Cd0.89Se, and Zn0.38Cd0.62Se when Zn content is 0.2, 0.5, and 0.8, respectively. In terms of the optical properties, the emission wavelength shifts from 512 to 545 nm with increasing Zn content from 0 to 0.8 while the QY changes from 89 to 45, respectively. Partial replacement of Cd by Zn is beneficial to improve the QY of Zn0.2and Zn0.5NCs. The optical properties of ternary NCs are affected by compositional effect rather than particle size effect.


2015 ◽  
Vol 242 ◽  
pp. 383-390
Author(s):  
Md Hosnay Mobarok ◽  
Tapas K. Purkait ◽  
Jonathan G.C. Veinot

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.


2012 ◽  
Vol 528 ◽  
pp. 272-276 ◽  
Author(s):  
Shan Ren ◽  
Li Qiang Li ◽  
Zhu Feng Liu ◽  
Ming Li ◽  
Lan Hong

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.


2016 ◽  
Vol 6 (6) ◽  
pp. 1264-1268
Author(s):  
F. A. Al-Mufadi ◽  
A. El-Taher ◽  
G. A. Gamal

Indium monoselenide (InSe) which is a layered semiconductor whose energy gap is 1.24 eV has received attention because of its potential applications in optoelectronic devices. In the present work n-type InSe crystals were grown by a special modification of the vertical Bridgman technique. X-ray Diffraction (XRD) patterns showed that all samples were single phased InSe. The crystals were irradiated with 100 - 500 KGy to reveal the influence of irradiation on the structural properties of the samples. Detailed structural analysis was done by Scherrerr’s procedures, x-ray peak broadening and Williamson–Hall plot methods to evaluate the crystalline sizes and lattice strain. Also from the relations between the irradiation dose and the deformation of the lattice parameters we could investigate and discuss the mutation of the dislocation density, grain size, microstrain and crystallinity of the grown crystals. Striking results are found due to irradiation in the present study for the first time.


Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 547 ◽  
Author(s):  
Mattia Pierpaoli ◽  
Mateusz Ficek ◽  
Michał Rycewicz ◽  
Mirosław Sawczak ◽  
Jakub Karczewski ◽  
...  

Carbon nanowalls (CNWs) have attracted much attention for numerous applications in electrical devices because of their peculiar structural characteristics. However, it is possible to set synthesis parameters to vary the electrical and optical properties of such CNWs. In this paper, we demonstrate the direct growth of highly transparent boron-doped nanowalls (B-CNWs) on optical grade fused quartz. The effect of growth temperature and boron doping on the behavior of boron-doped carbon nanowalls grown on quartz was studied in particular. Temperature and boron inclusion doping level allow for direct tuning of CNW morphology. It is possible to operate with both parameters to obtain a transparent and conductive film; however, boron doping is a preferred factor to maintain the transparency in the visible region, while a higher growth temperature is more effective to improve conductance. Light transmittance and electrical conductivity are mainly influenced by growth temperature and then by boron doping. Tailoring B-CNWs has important implications for potential applications of such electrically conductive transparent electrodes designed for energy conversion and storage devices.


2018 ◽  
Vol 2 (12) ◽  
pp. 2263-2271 ◽  
Author(s):  
Jianbo Xiong ◽  
Xinyue Li ◽  
Chunqing Yuan ◽  
Sergey Semin ◽  
Zhaoquan Yao ◽  
...  

Studies of the non-linear optical properties of classical AIEgens are rare, despite their important potential applications in organic composite photonic circuits. Here, we present experimental results, supported by theoretical calculations, of the non-linear optical (NLO) properties of TPE and its halogenated derivates.


Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 510 ◽  
Author(s):  
Jianhang Shi ◽  
Yanxin Wang ◽  
Linjun Huang ◽  
Peng Lu ◽  
Qiuyu Sun ◽  
...  

A novel anhydrous preparation of silica (SiO2)-encapsulated terbium (Tb3+) complex nanoparticles has been investigated. The SiO2-Tb3+ nanoparticles are incorporated in electrospun polyvinylpyrrolidone hybrid nanofibers. Transmission electron microscopy confirms that Tb3+ complexes are uniformly and stably encapsulated in or carried by nanosilica. The influence of pH on the fluorescence of Tb3+ complexes is discussed. The properties, composition, structure, and luminescence of the resulting SiO2–Tb3+ hybrid nanoparticles are investigated in detail. There is an increase in the fluorescence lifetime of SiO2–Tb3+ nanoparticles and SiO2–Tb3+/polyvinylpyrrolidone (PVP) hybrid nanofibers compared with the pure Tb3+ complexes. Due to the enhanced optical properties, the fluorescent hybrid nanofibers have potential applications as photonic and photoluminescent materials.


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