Lead diiodide (PbI2) energy gaps, band edge transition energies

Author(s):  
2021 ◽  
Vol 9 (4) ◽  
pp. 222-227
Author(s):  
Genichi Motomura ◽  
Yukiko Iwasaki ◽  
Tatsuya Kameyama ◽  
Tsukasa Torimoto ◽  
Taro Uematsu ◽  
...  

1989 ◽  
Vol 160 ◽  
Author(s):  
M.-E. Pistol ◽  
M. Gerling ◽  
A. Gustafsson ◽  
G. Paulsson ◽  
L. Samuelson ◽  
...  

AbstractStrained layers of indirect GaAsP have been grown on the (111)B-oriented surface of GaP by Metal-Organic Vapour Phase Epitaxy (MOVPE). These layers have been characterized by low-temperature photoluminescence (PL), electroreflectance (ER), secondary-ion mass spectroscopy (SIMS), and wavelength resolved imaging cathodoluminescence (CL). We have been able to follow the transition energies of the lowest X conduction band edge, as well as the higher Γ band edge of the strained layers, as a function of composition up to an As-concentration of 38 %. The experimental values of the transition energies are compared with predictions made from calculations based on deformation potential theory. CL allows us to directly observe the onset of dislocation formation, i. e. the critical thickness. The appearance and properties of the dislocation network revealed by CL are very different from those of the corresponding network when the strained layers are grown on (001)-oriented surfaces.


2013 ◽  
Vol 848 ◽  
pp. 302-306
Author(s):  
Wen Li Zheng ◽  
Wei Yang

A comparative study worked on crystal morphology and luminescence characteristic by hydrothermal method with mineralizer of 3 mol /L KOH, fill factor of 35%, under the condition of three kinds of mineralizers which included 3 mol /L KOH in sample 1, 3 mol /L KOH and 1 mol /L LiOH in sample 2, 3 mol /L KOH and CaO: Zn ( OH) 2 = 2% (amount of substance percentage). Nonpolar ZnO crystals were synthesized by adding proper proportion of CaO or LiOH,the speed of growth along c-axic was weakened obviously. The obtained ZnO crystals exposed more areas on the positive polar face c { 0001}. meanwhile,it exposed negative polar-c {000},positive pyramidal face + p { 101},negative pyramidal face-p {10} and hexagonal faces m {1010}. Only KOH or LiOH auxiliarily added,the emission spectrum was only visible light,no UV light from band edge transition, indicating that the crystal defects luminous center are numerous. A strong UV band emitting from band edge transition was in luminescent spectrumn of the prepared crystals by adding CaO,which indicated a decrease in defects luminous center.


2007 ◽  
Vol 31 ◽  
pp. 236-241
Author(s):  
Mahi R. Singh

We have studied the quantum information processing phenomenon in photonic crystals doped with four-level nanoparticles. This phenomenon occurs due to the switching mechanism in the system. We consider that one of the transition energies of nanoparticles is coupled near resonantly with a photonic band gap edge. The dipole-dipole interaction between the nanoparticles has also been included. It is found that the system switches between the transparent and nontransparent states due to the dipole-dipole interaction and the band edge coupling. This is an interesting finding and can be used to produce logical photon switches in the quantum information processing.


1996 ◽  
Vol 449 ◽  
Author(s):  
Xiao Tang ◽  
Fazla R. B. Hossain ◽  
Kobchat Wongchotigul ◽  
Michael G Spencer

ABSTRACTThe Cathodoluminescence (CL) measurements of undoped and carbon doped aluminum nitride (AlN) thin films near the band-edge region were performed at 300, 77 and 4.2 K, respectively. These films were grown on three different substrates: 6H-SiC, 4H-SiC and sapphire. A dominant peak was observed in undoped samples around 5.9 eV. This peak can be further resolved into three distinct peaks at 6.05, 5.85, and 5.69 eV for AlN on sapphire. The temperature dependence of the peak positions and line widths were investigated. These peaks are believed to be due to exciton recombination. Also, the absorption spectra of carbon doped AlN on sapphire were analyzed to study the Urbach tail parameters which play an important role in near band-edge transitions.


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