Breaking through the "3.0 eV wall" of energy band gap in mid-infrared nonlinear optical rare earth chalcogenides by charge-transfer engineering

2021 ◽  
Author(s):  
Dajiang Mei ◽  
Wangzhu Cao ◽  
Naizheng Wang ◽  
Xing-Xing Jiang ◽  
Jun Zhao ◽  
...  
Keyword(s):  
Rare Earth ◽  
Charge Transfer ◽  
Band Gap ◽  
Energy Band ◽  
Nonlinear Optical ◽  
Molecular Design ◽  
Energy Band Gap ◽  
Mid Infrared ◽  
Challenging Issue ◽  
Nlo Response

Increasing the energy band gap under the premise to maintain a large nonlinear optical (NLO) response is a challenging issue for the exploration and molecular design of mid-infrared nonlinear optical...

scholarly journals Exploration of Nonlinear Optical Properties of Triphenylamine-Dicyanovinylene Coexisting Donor-π-Acceptor Architecture by the Modification of π-Conjugated Linker

2021 ◽  
Vol 8 ◽  
Author(s):  
Muhammad Usman Khan ◽  
Muhammad Khalid ◽  
Sumreen Asim ◽  
Momina ◽  
Riaz Hussain ◽  
...  
Keyword(s):  
Band Gap ◽  
Energy Band ◽  
Nonlinear Optical ◽  
Frontier Molecular Orbital ◽  
High Tech ◽  
First Hyperpolarizability ◽  
Energy Band Gap ◽  
Nlo Properties ◽  
Nlo Response ◽  
The Impact

High-tech electronic, optics, and storage devices require organic compounds with nonlinear optical (NLO) properties. This study designed D-π-A based dyes with donor triphenylamine (TPA) and acceptor dicyanovinylene (DCV) species by structurally modifying π-conjugated linkers. Our density functional theory (DFT) computations analyzed the impact of structural variations on the nonlinear optical (NLO) response of newly designed dyes. The B3LYP/6-31G(d,p) level determined the quantic chemical insights: frontier molecular orbital (FMOs), natural bond orbitals (NBOs), and nonlinear optical (NLO) properties of the designed dyes (DPTM-1 to DPTM-12). UV-Vis analysis based on the TD-DFT/CAM-B3LYP/6-311+G(d,p) level explored the optoelectronic properties. DPTM-1 and DPTM-5 showed the highest red-shifted absorption band at 519 and 506 nm. NBO analysis shows that DPTM-1 to DPTM-12 dyes have positive values for all donors (D) and π-spacers but negative values for acceptors (A). The π-spacers act as a conveyer between donor and acceptor moieties; thus, electrons were transferred smoothly from D to A units, which resulted in a charge separation state. Our calculations show the extent of NLO response in terms of electronic transitions, polarizability <α>, and first hyperpolarizability (β) values. The highest value of βtotal was 110,509.23 a.u. manifested in DPTM-6 due to 2,5-dimethyloxazole as a second π-linker, twice that of R (66,275.95 a.u.). Also, DPTM-6 and DPTM-8 exhibit the lowest energy band gap of 2.06 and 2.04 eV, respectively. In short, all DPTM-1 to DPTM-12 dyes manifested maximum absorption, lowest energy band gap, greater charge transfer from donor to the acceptor, and better first hyperpolarizability values as compared to the R and showed good NLO response. The present work represents new compounds with remarkable NLO properties and their applications in modern high-tech devices.

The Role of Rare Earths in Narrow Energy Gap Semiconductors

1990 ◽  
Vol 216 ◽  
Author(s):  
D.L. Partin ◽  
J. Heremans ◽  
D.T. Morelli ◽  
C.M. Thrush
Keyword(s):  
Rare Earth ◽  
Band Gap ◽  
Indium Antimonide ◽  
Energy Band ◽  
Energy Gap ◽  
Lattice Parameter ◽  
Molecular Beam Epitaxy Growth ◽  
Lead Chalcogenide ◽  
Energy Band Gap

ABSTRACTNarrow energy band gap semiconductors are potentially useful for various devices, including infrared detectors and diode lasers. Rare earth elements have been introduced into lead chalcogenide semiconductors using the molecular beam epitaxy growth process. Europium and ytterbium increase the energy band gap, and nearly lattice-matched heterojunctions have been grown. In some cases, valence changes in the rare earth element cause doping of the alloy. Some initial investigations of the addition of europium to indium antimonide will also be reported, including the variation of lattice parameter and optical transmission with composition and a negative magnetoresistance effect.

Energy band gap engineering in borate ultraviolet nonlinear optical crystals:ab initiostudies

2012 ◽  
Vol 24 (14) ◽  
pp. 145503 ◽  
Author(s):  
Ran He ◽  
Z S Lin ◽  
Tao Zheng ◽  
He Huang ◽  
C T Chen
Keyword(s):  
Band Gap ◽  
Energy Band ◽  
Nonlinear Optical ◽  
Energy Band Gap ◽  
Band Gap Engineering

scholarly journals No Resistive Normal Electrons in Beginning Superconducting States

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1512
Author(s):  
Changho Seo ◽  
Seongsoo Cho ◽  
Je Huan Koo
Keyword(s):  
Band Gap ◽  
Energy Band ◽  
Energy Band Gap

We investigate why normal electrons in superconductors have no resistance. Under the same conditions, the band gap is reduced to zero as well, but normal electrons at superconducting states are condensed into this virtual energy band gap.

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

Energy band gap of the alloy Zn1−xMgxSeyTe1−y lattice matched to ZnTe, InAs and InP

2000 ◽  
Vol 214-215 ◽  
pp. 350-354 ◽  
Author(s):  
Kyurhee Shim ◽  
Herschel Rabitz ◽  
Ji-Ho Chang ◽  
Takafumi Yao
Keyword(s):  
Band Gap ◽  
Energy Band ◽  
Energy Band Gap ◽  
Lattice Matched
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