Composite Semiconductor Nanoparticles

1992 ◽  
Vol 283 ◽  
Author(s):  
H. S. Zhou ◽  
I. Honma ◽  
H. Komiyama ◽  
J. W. Haus
Keyword(s):  
Electron Diffraction ◽  
Optical Absorption ◽  
Theoretical Calculation ◽  
Band Gap ◽  
Semiconductor Nanoparticles ◽  
Core Radius ◽  
Nanometer Size ◽  
Effective Masses ◽  
The Core ◽  
Semiconductor Particles

ABSTRACTNanometer size semiconductor particles coated with another semiconductor can exhibit unusual and interesting phenomena associated with the redistribution of the electron and hole wavefunctions. Using the band offsets and effective-masses, the band gap as well as the wavefunctions can be altered by changing the core radius of the particles. CdS/PbS coated semiconductor nanoparticles are synthesized by ion displacing method and experimental results are discussed along with the theoretical calculation. Optical absorption as well as TEM, Electron diffraction results provides for the evidence that the particles are coated.

Interband optical absorption in wurtzite GaN/InxGa1−xN/GaN spherical quantum dots with built-in electric field

2019 ◽  
Vol 33 (30) ◽  
pp. 1950367 ◽  
Author(s):  
X. M. Cao ◽  
W. H. Liu ◽  
X. C. Yang ◽  
Y. Qu ◽  
Y. Xing
Keyword(s):  
Optical Absorption ◽  
Electric Field ◽  
Mixed Crystal ◽  
Refraction Index ◽  
Core Radius ◽  
The Finite Element Method ◽  
Absorption Coefficients ◽  
The Core ◽  
Spherical Core ◽  
Index Changes

Based on the principle of density matrix and the finite element method, the interband optical absorption between the electron and hole has been investigated in a wurtzite [Formula: see text] spherical core–shell quantum dot (CSQD) including a strong built-in electric field (BEF). We have studied the effects of the size and the ternary mixed crystal on the optical absorption coefficients (ACs) and refraction index changes (RICs). The results indicate that the absorption peaks of ACs and RICs decrease rapidly, and show a redshift with the increase of the component [Formula: see text]. It is also found that the absorption peaks of ACs and RICs reduce obviously and depend on the core radius and the well width. When the core radius increases, the positions of the maximum ACs and RICs show a blueshift. At the same time, it presents a redshift when the well width increases. Particularly, the influence of the well width is much stronger than the core radius in the wurtzite [Formula: see text] spherical CSQDs. We hope that these results could provide guidance on both theoretical and experimental study related to the optical properties of spherical CSQDs.

Optical absorption and band gap shift of n-doped Al Ga1−As alloys grown by MBE

1998 ◽  
Vol 43-44 ◽  
pp. 423-429 ◽  
Author(s):  
A. Ferreira da Silva ◽  
C. Persson ◽  
K.-F. Berggren ◽  
I. Pepe ◽  
A. Santos Alves ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Band Gap

scholarly journals Characteristic Analysis and Structural Design of Hollow-Core Photonic Crystal Fibers with Band Gap Cladding Structures

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 284
Author(s):  
Bowei Wan ◽  
Lianqing Zhu ◽  
Xin Ma ◽  
Tianshu Li ◽  
Jian Zhang
Keyword(s):  
Photonic Crystal ◽  
Band Gap ◽  
Photonic Crystal Fibers ◽  
Relative Sensitivity ◽  
Confinement Loss ◽  
Hollow Core ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
The Core ◽  
Crystal Fibers

Due to their flexible structure and excellent optical characteristics hollow-core photonic crystal fibers (HC-PCFs) are used in many fields, such as active optical devices, communications, and optical fiber sensing. In this paper, to analyze the characteristics of HC-PCFs, we carried out finite element analysis and analyzed the design for the band gap cladding structure of HC-PCFs. First, the characteristics of HC19-1550 and HC-1550-02 in the C-band were simulated. Subsequently, the structural optimization of the seven-cell HC-1550-02 and variations in characteristics of the optimized HC-1550-02 in the wavelength range 1250–1850 nm were investigated. The simulation results revealed that the optimal number of cladding layers is eight, the optimal core radius is 1.8 times the spacing of adjacent air holes, and the optimal-relative thickness of the core quartz-ring is 2.0. In addition, the low confinement loss bandwidth of the optimized structure is 225 nm. Under the transmission bandwidth of the optimized structure, the core optical power is above 98%, the confinement loss is below 9.0 × 10−3 dB/m, the variation range of the effective mode field area does not exceed 10 μm2, and the relative sensitivity is above 0.9570. The designed sensor exhibits an ultra-high relative sensitivity and almost zero confinement loss, making it highly suitable for high-sensitivity gas or liquid sensing.

Energy Band Gap Studies of CdS Nanomaterials

2008 ◽  
Vol 3 ◽  
pp. 97-102 ◽  
Author(s):  
Dinu Patidar ◽  
K.S. Rathore ◽  
N.S. Saxena ◽  
Kananbala Sharma ◽  
T.P. Sharma
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Energy Band ◽  
Chemical Method ◽  
Optical Absorption Spectroscopy ◽  
Cds Nanoparticles ◽  
X Ray Diffraction ◽  
Energy Band Gap ◽  
X Ray ◽  
Simple Chemical

The CdS nanoparticles of different sizes are synthesized by a simple chemical method. Here, CdS nanoparticles are grown through the reaction of solution of different concentration of CdCl2 with H2S. X-ray diffraction pattern confirms nano nature of CdS and has been used to determine the size of particle. Optical absorption spectroscopy is used to measure the energy band gap of these nanomaterials by using Tauc relation. Energy band gap ranging between 3.12 eV to 2.47 eV have been obtained for the samples containing the nanoparticles in the range of 2.3 to 6.0 nm size. A correlation between the band gap and size of the nanoparticles is also established.

Tailoring energy band gap and optical absorption of Cd doped MnTe2

2020 ◽  
pp. 111059
Author(s):  
B. Thapa ◽  
P.K. Patra ◽  
Sandeep Puri ◽  
K. Neupane ◽  
A. Shankar
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Energy Band ◽  
Energy Band Gap

NEAR BAND GAP OPTICAL ABSORPTION IN SEMICONDUCTING VO2

1976 ◽  
Vol 37 (C4) ◽  
pp. C4-59-C4-62 ◽  
Author(s):  
P. MERENDA ◽  
D. KAPLAN ◽  
C. SOMMERS
Keyword(s):  
Optical Absorption ◽  
Band Gap

scholarly journals Band Gap Determination of Copper Doped Tungsten Diselenide Single Crystals by Optical Absorption Method

2012 ◽  
Vol 1 (2) ◽  
pp. 149-153 ◽  
Author(s):  
M. P. Deshpande ◽  
M. N. Parmar ◽  
Nilesh N. Pandya ◽  
Sandip V. Bhatt ◽  
Sunil Chaki
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Single Crystals ◽  
Absorption Method ◽  
Tungsten Diselenide ◽  
Determination Of Copper

Visible Electro- and Photoluminescence from Porous Silicon and its Related Optoelectronic Properties

1991 ◽  
Vol 256 ◽  
Author(s):  
Nobuyoshi Koshida ◽  
Hideki Koyama
Keyword(s):  
Porous Silicon ◽  
Optical Absorption ◽  
Size Effect ◽  
Band Gap ◽  
Visible Region ◽  
Optoelectronic Properties ◽  
Porous Si ◽  
Quantum Size ◽  
Effect Model ◽  
Injection Type

ABSTRACTThe optoelectronic properties of porous Si (PS) are presented in terms of electroluminescence (EL), photoluminescence (PL), photoconduction (PC), and optical absorption. Observations of injection-type EL, efficient PL, band-gap widening, and photosensitivities In the visible region are consistent with the quantum size effect model in PS.

Sign in / Sign up

Export Citation Format

Share Document