Synthesis of Colloidal InP/ZnS Nanocrystals for a Photosensitizer

2012 ◽  
Vol 1409 ◽  
Author(s):  
Seungyong Lee ◽  
Vanga R. Reddy ◽  
Jiang Wu ◽  
Rick Eyi ◽  
Omar Manasreh
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Chemical Stability ◽  
Semiconductor Nanocrystals ◽  
Solar Spectrum ◽  
Core Shell ◽  
Direct Band Gap ◽  
Direct Band ◽  
Zns Nanocrystals ◽  
Spectrum Region

ABSTRACTIts intrinsic nontoxicity makes the direct band gap InP/ZnS core/shell be one of the most promising semiconductor nanocrystals for optoelectric applications, with the advantage of tuning the optical absorption range in the desired solar spectrum region. Highly luminescent and monodisperse InP/ZnS nanocrystals were synthesized in a non-coordinating solvent under a thorough degassing process. By varying synthesis scheme, different size InP/ZnS nanocrystals were grown. For the purpose of ensuring air stability, ZnS shell was grown. This ZnS shell improves the chemical stability in terms of oxidation prevention. Measurements of absorption and emission were performed on different InP/ZnS nanocrystals with different sizes. As expected, the measurements show a red-shift as the size of the InP/ZnS nanocrystals increased.

scholarly journals Optical Absorption Exhibits Pseudo-Direct Band Gap of Wurtzite Gallium Phosphide

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Bruno C. da Silva ◽  
Odilon D. D. Couto ◽  
Hélio T. Obata ◽  
Mauricio M. de Lima ◽  
Fábio D. Bonani ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Gallium Phosphide ◽  
Direct Band Gap ◽  
Direct Band

scholarly journals Author Correction: Optical Absorption Exhibits Pseudo-Direct Band Gap of Wurtzite Gallium Phosphide

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Bruno C. da Silva ◽  
Odilon D. D. Couto ◽  
Hélio T. Obata ◽  
Mauricio M. de Lima ◽  
Fábio D. Bonani ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Gallium Phosphide ◽  
Direct Band Gap ◽  
Direct Band

Preparation and Characterization of Cu2Zn(GexSn1-x)Se4 Thin-films from Sputtered Elemental Precursors

2014 ◽  
Vol 1670 ◽  
Author(s):  
Antony Jan ◽  
Yesheng Yee ◽  
Bruce M. Clemens
Keyword(s):  
Band Gap ◽  
Low Cost ◽  
Solar Spectrum ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Material System ◽  
Direct Band Gap ◽  
Glass Substrates ◽  
Before And After ◽  
Direct Band

ABSTRACTThin-film absorber layers for photovoltaics have attracted much attention for their potential for low cost per unit power generation, due both to reduced material consumption and to higher tolerance for defects such as grain boundaries. Cu2ZnGeSe4 (CZGSe) comprises one such material system which has a near-optimal direct band gap of 1.6 eV for absorption of the solar spectrum, and is made primarily from earth-abundant elements.CZGSe metallic precursor films were sputtered from Cu, Zn, and Ge onto Mo-coated soda lime glass substrates. These were then selenized in a two-zone close-space sublimation furnace using elemental Se as the source, with temperatures in the range of 400 to 500 C, and at a variety of background pressures. Films approximately 1-1.5 µm thick were obtained with the expected stannite crystal structure.Next, Cu2ZnSnSe4 (CZTSe), which has a direct band gap of 1.0 eV, was prepared in a similar manner and combined with CZGSe as either compositionally homogeneous or layered absorbers. The compositional uniformity of selenide absorbers made by selenizing compositionally homogeneous Cu-Zn-Ge-Sn precursor layers was determined and the band gap as a function of composition was investigated in order to demonstrate that the band gap is tuneable for a range of compositions. For layered Cu-Zn-Ge/Cu-Zn-Sn precursor films, the composition profile was measured before and after selenization to assess the stability of the layered structure, and its applicability for forming a band-gap-graded device for improved current collection.

scholarly journals Growth and Optical Properties of Direct Band Gap Ge/Ge0.87Sn0.13 Core/Shell Nanowire Arrays

Nano Letters ◽  
2017 ◽  
Vol 17 (3) ◽  
pp. 1538-1544 ◽  
Author(s):  
S. Assali ◽  
A. Dijkstra ◽  
A. Li ◽  
S. Koelling ◽  
M. A. Verheijen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Nanowire Arrays ◽  
Core Shell ◽  
Direct Band Gap ◽  
Direct Band

Pressure coefficient of the direct band gap ofAlxGa1−xAsfrom optical absorption measurements

1979 ◽  
Vol 20 (6) ◽  
pp. 2398-2400 ◽  
Author(s):  
N. Lifshitz ◽  
A. Jayaraman ◽  
R. A. Logan ◽  
R. G. Maines
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Pressure Coefficient ◽  
Direct Band Gap ◽  
Direct Band ◽  
Absorption Measurements

Photovoltaic Performance of Thin-Film CdTe for Solar Cell Applications

2021 ◽  
Vol 10 (1) ◽  
pp. 91-97
Author(s):  
A. Hendi ◽  
R. Alkhraif ◽  
H. Alshehri ◽  
F. AlKallas ◽  
M. Almoneef ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Optical Absorption ◽  
Band Gap ◽  
Photovoltaic Performance ◽  
Open Circuit ◽  
Potential Candidate ◽  
Direct Band Gap ◽  
Theoretical Support ◽  
Direct Band

In the current investigation, we report a theoretical study to acquire the highest feasible efficiency of cadmium telluride (CdTe) thin-films. It is well recognized that CdTe crystallizes in cubic zinc-blende structure and its direct band gap of 1.5 eV turned it out as a potential candidate for photovoltaic (PV) applications. Our calculations are founded on Shockley-Queisser (SQ) limit to simulate the open-circuit voltage, current density, and filling factor versus the variation of photon energy up to 4.0 eV. These key parameters of SQ change with the variation of energy between 0.3 to 3.5 eV. This is owing to the strong optical absorption (> 104 cm−1) and direct band gap of 1.5 eV, which make CdTe thin-film suitable for single junction solar cell and ideal for PV applications. It is observed that the optical absorption enhances as the thickness of the absorbed layer increases. This will effectively provide a theoretical support to the industry of global solar energy that is anticipated to be sustainable in the future.

Can Tauc plot extrapolation be used for direct-band-gap semiconductor nanocrystals?

2015 ◽  
Vol 117 (12) ◽  
pp. 125701 ◽  
Author(s):  
Y. Feng ◽  
S. Lin ◽  
S. Huang ◽  
S. Shrestha ◽  
G. Conibeer
Keyword(s):  
Band Gap ◽  
Semiconductor Nanocrystals ◽  
Direct Band Gap ◽  
Tauc Plot ◽  
Direct Band
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