Features of current transfer in variable band-gap structures

1994 ◽  
Vol 37 (9) ◽  
pp. 819-822
Author(s):  
V. G. Savitskii ◽  
B. S. Sokolovskii
Keyword(s):  
Band Gap ◽  
Current Transfer ◽  
Variable Band Gap

Buried (Fe1 −x Co x )Si2 layers with variable band gap formed by ion beam synthesis

1996 ◽  
Vol 62 (2) ◽  
pp. 155-162 ◽  
Author(s):  
D. Panknin ◽  
E. Wieser ◽  
W. Skorupa ◽  
W. Henrion ◽  
H. Lange
Keyword(s):  
Band Gap ◽  
Ion Beam ◽  
Ion Beam Synthesis ◽  
Variable Band Gap

Variable Band Gap Poly(arylene ethynylene) Conjugated Polyelectrolytes

2006 ◽  
Vol 39 (19) ◽  
pp. 6355-6366 ◽  
Author(s):  
Xiaoyong Zhao ◽  
Mauricio R. Pinto ◽  
Lindsay M. Hardison ◽  
Jeremiah Mwaura ◽  
Juergen Müller ◽  
...  
Keyword(s):  
Band Gap ◽  
Conjugated Polyelectrolytes ◽  
Variable Band Gap

Variable band gap conjugated polymers for optoelectronic and redox applications

2005 ◽  
Vol 20 (12) ◽  
pp. 3188-3198 ◽  
Author(s):  
Young-Gi Kim ◽  
Barry C. Thompson ◽  
Nisha Ananthakrishnan ◽  
G. Padmanaban ◽  
S. Ramakrishnan ◽  
...  
Keyword(s):  
Phase Separation ◽  
Conjugated Polymers ◽  
Band Gap ◽  
Conjugated Polymer ◽  
Narrow Band ◽  
Acid Methyl Ester ◽  
Light Emitting ◽  
Donor And Acceptor ◽  
Color Tunable ◽  
Variable Band Gap

We report here on the utilization of variable band gap conjugated polymers for optoelectronic redox applications comprising organic photovoltaics, color tunable light emitting diodes, and electrochromics. For the evaluation of morphology in photovoltaicdevices, atomic force microscopy, and optical microscopy provided direct visualization of the blend film structure. The evolution of the morphology in two and three component blends incorporating poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenlenevinylene] (MEH-PPV), poly(methylmethacrylate) (PMMA), and [6, 6]-phenyl C61-butyric acid methyl ester (PCBM) was investigated. It was found that while insulating PMMA can be used to modulate the phase separation in these blends, a bicontinuous network of donor and acceptor was required to achieve the best device results. Similarily, a MEH-PPVcopolymer with a decreased conjugation length has been used for investigating inter- and intramolecular photoinduced charge transfer in the presence of PMMA and PCBM.We fabricated MEH-PPV/PCBM solar cells that have power conversion efficiencies up to 1.5% with a range of 0.7–1.5%, dependent on the nature of the MEH-PPV used. This further indicates that in addition to blend morphology, polymer structure is critical for optimizing device performance. To this end, the concept of an ideal donor for photovoltaic devices based on poly[2,5-di(3,7-dialkoxy)-cyanoterephthalylidene] is described and two donor-acceptor polymers based on cyanovinylene (CNV) and dioxythiophene are discussed as representative examples of soluble narrow band gap polymers synthesized in our group. For light emitting applications, utilization of two blue emitting conjugated polymers poly (9,9-dioctylfluorene) (PFO) and poly[(9,9-dihexylfluorenyl-2,7-diyl)-co-(9,ethyl-3,6-carbazole)] (PFH-PEtCz)is presented for a color tunable polymer light emitting diode that emits orange, green, and blue light with a voltage range of 7–10 V as a function of the total conjugated polymer content in PMMA and is attributed to the phase separation between the conjugated polymers. Finally, the narrow band gap conjugated polymer, poly[bis(3,4-propylenedioxythiophene-dihexyl)]-cyanovinylene has been characterized for its electrochromic properties, illustrating the multifunctional nature of variable band gap conjugated polymers.

Thermal Annealing Study of Variable Band-Gap a-SiN:H Alloy Films

2001 ◽  
Vol 664 ◽  
Author(s):  
N. Banerji ◽  
E. Faro ◽  
J. Serra
Keyword(s):  
Band Gap ◽  
Thermal Annealing ◽  
Morphological Changes ◽  
Near Neighbor ◽  
Alloy Films ◽  
Bond Stability ◽  
Neighbor Environment ◽  
Annealing Study ◽  
The Stability ◽  
Variable Band Gap

ABSTRACTA study of the effects of thermal annealing on the bond structure, optical properties, morphology and stoichiometry of variable band gap a-SixNyHz alloy films deposited by ArF LCVD has been made. These films were generated through two different photochemical pathways resulting from the use of either SiH4/NH3 or Si2H6/NH3 as precursor gases. Thermal annealing study of these films which span a wide compositional (0.22 < x/y < 1.44) and band-gap (Eg) range (1.7–5.2 eV) has led to the analysis of the stability of different bond configurations. We report here hydrogen bond stability and rearrangement of the near-neighbor environment of SiN bonds analyzed through FTIR, refractive index variations measured by ellipsometry and surface morphological changes observed through AFM during to the process of annealing. Results indicate that in the SiH4/NH3 deposited nitrogen-rich SiN:H films, SiHn bonds persist even upto 900°C and SiH bonds are less thermally stable than SiH2. Also, while the total bonded hydrogen decreases, the extent of SiN bond increases through a reaction mechanism involving: SiH + NH → SiN + H2. In the Si2H6/NH3 deposited silicon-rich film, whose initial spectra shows Si-H stretching and Si-H wagging bands, a rapid loss of Si-H bonds occurs at T ≤ 650°C. Based on the bond configurational interpretations of the Random bonding model proposed by Bustarret, we calculate the variations in film stoichiometry and density with the annealing temperature.

Novel electronic and optical properties of ultrathin silicene/arsenene heterostructures and electric field effects

2017 ◽  
Vol 19 (16) ◽  
pp. 10644-10650 ◽  
Author(s):  
Huabing Shu ◽  
Yilong Tong ◽  
Jiyuan Guo
Keyword(s):  
Optical Properties ◽  
Optical Absorption ◽  
Electric Field ◽  
Band Gap ◽  
Absorption Spectra ◽  
Optical Absorption Spectra ◽  
Electric Field Effects ◽  
Electronic And Optical Properties ◽  
Vertical Electric Field ◽  
Variable Band Gap

The variable band-gap of the Si/As heterostructure (left) and optical absorption spectra for AA-stacking under a vertical electric field (right).

Spin-splitting of electron subbands in semiconducting films with a variable band gap

2007 ◽  
Vol 369 (1-2) ◽  
pp. 140-145 ◽  
Author(s):  
Yong S. Joe ◽  
Leonid S. Isaev ◽  
Arkady M. Satanin
Keyword(s):  
Band Gap ◽  
Spin Splitting ◽  
Variable Band Gap

scholarly journals Simulating the spectral characteristics of reflection in planar porous structures with antireflection coatings ZnS/DyF3

2021 ◽  
Vol 2086 (1) ◽  
pp. 012168
Author(s):  
D Shishkina ◽  
I Shishkin ◽  
P Tishin
Keyword(s):  
Porous Silicon ◽  
Band Gap ◽  
Matrix Method ◽  
Multilayer Structure ◽  
Spectral Characteristics ◽  
Porous Structures ◽  
Antireflection Coatings ◽  
Real Experiment ◽  
The Real ◽  
Variable Band Gap

Abstract This paper presents the results of modeling a planar multilayer structure with layers of porous silicon, ZnS and DyF3 coatings by the optical matrix method. It was shown that the optical matrix method, taking into account the model of porous silicon with a variable band gap, which takes into account the porosity gradient, allows us to approximate the course of the curve of the real experiment

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