Influence of ion bombardment on the photoluminescence response of embedded CdS nanoparticles

Open Physics ◽  
2006 ◽  
Vol 4 (2) ◽  
Author(s):  
Dambarudhar Mohanta ◽  
Fouran Singh ◽  
D. Avasthi ◽  
Amarjyoti Choudhury
Keyword(s):  
Light Emission ◽  
Ion Irradiation ◽  
Energy Shift ◽  
Band Edge ◽  
Cds Nanoparticles ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Chemical Route ◽  
Host Matrix ◽  
Gold Ion

AbstractSemiconductor nanoparticles (CdS) were fabricated by an inexpensive chemical route using polyvinyl alcohol (PVA) as the dielectric host matrix. Nano-CdS in PVA were subjected to ion irradiation (using oxygen, chlorine and gold) in the medium energy range (80–100 MeV) and under fluence variation of 1011–1013 ions/cm2. The nature of light emission was found to be drastically different in each of the three cases. Photoluminescence spectra of oxygen irradiated samples exhibit band edge emission (2.8 eV) as well as trap related emission (1.76 eV) whereas band edge emission is found to be bleached out for chlorine ion irradiated nano-CdS. The intense broad PL peaks, noticeable in the case of gold ion irradiated samples suggest superposition of the two peaks — namely, band edge emission and trap related emission. Furthermore, in the case of gold ion irradiated nano-CdS, energy shift in the PL spectra reveals variation in size distribution caused by the extra pressure effect of heavy gold ion beams. The mechanism of such a difference as a result of ion irradiation-type and ion-fluence is discussed in detail.

Visible Light Emission from Ordered Nanopatterned InP Surface

2007 ◽  
Vol 31 ◽  
pp. 56-58
Author(s):  
S.K. Mohanta ◽  
R.K. Soni ◽  
S. Tripathy ◽  
Soo Jin Chua
Keyword(s):  
Emission Band ◽  
Light Emission ◽  
Surface Region ◽  
Normal Incidence ◽  
Wavelength Dependence ◽  
Visible Emission ◽  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Band Emission

The InP nanostructures have been fabricated by low-energy Ar+-ion of dose 1 × 1018 cm-2 and energy 50 keV, at normal incidence. The InP nanodot size varies from 50 to 90 nm. Photoluminescence spectra show blue shifted visible emission band at 1.98 eV, and quenching of the band edge emission from the nanopatterned surface. The blue-shifted emission band arises due to size convoluted band-to-band emission form the surface nanodots while the defects formation in the irradiated surface leads to the quenching of band edge emission. Thermal annealing results in clustering of the patterned surface and enhancement of the band edge emission accompanied with absence of visible band. Our results show that the origin of visible emission is from the surface nanodots and not from the nanocrystallites in the implanted surface region. This is corroborated by the wavelength dependence of photoluminescence measurement by probing different depth of the disordered region.

scholarly journals Core Nanoparticle Engineering for Narrower and More Intense Band-Edge Emission from AgInS2/GaSx Core/Shell Quantum Dots

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1763 ◽  
Author(s):  
Watcharaporn Hoisang ◽  
Taro Uematsu ◽  
Takahisa Yamamoto ◽  
Tsukasa Torimoto ◽  
Susumu Kuwabata
Keyword(s):  
Surface Passivation ◽  
Precursor Solution ◽  
Silver Sulfide ◽  
Band Edge ◽  
Crystal Phase ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Orthorhombic Crystal ◽  
Metal Precursor ◽  
Ag2s Nanoparticles

Highly luminescent silver indium sulfide (AgInS2) nanoparticles were synthesized by dropwise injection of a sulfur precursor solution into a cationic metal precursor solution. The two-step reaction including the formation of silver sulfide (Ag2S) nanoparticles as an intermediate and their conversion to AgInS2 nanoparticles, occurred during the dropwise injection. The crystal structure of the AgInS2 nanoparticles differed according to the temperature of the metal precursor solution. Specifically, the tetragonal crystal phase was obtained at 140 °C, and the orthorhombic crystal phase was obtained at 180 °C. Furthermore, when the AgInS2 nanoparticles were coated with a gallium sulfide (GaSx) shell, the nanoparticles with both crystal phases emitted a spectrally narrow luminescence, which originated from the band-edge transition of AgInS2. Tetragonal AgInS2 exhibited narrower band-edge emission (full width at half maximum, FWHM = 32.2 nm) and higher photoluminescence (PL) quantum yield (QY) (49.2%) than those of the orthorhombic AgInS2 nanoparticles (FWHM = 37.8 nm, QY = 33.3%). Additional surface passivation by alkylphosphine resulted in higher PL QY (72.3%) with a narrow spectral shape.

Stable enhancement of near-band-edge emission of ZnO nanowires by hydrogen incorporation

2010 ◽  
Vol 21 (6) ◽  
pp. 065709 ◽  
Author(s):  
A Dev ◽  
R Niepelt ◽  
J P Richters ◽  
C Ronning ◽  
T Voss
Keyword(s):  
Zno Nanowires ◽  
Band Edge ◽  
Near Band Edge Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Hydrogen Incorporation

Using dispersion theory to interpret the polarization properties of the band-edge emission in GaN crystals

1987 ◽  
Vol 61 (6) ◽  
pp. 381-384
Author(s):  
Bao Qingcheng ◽  
Zhang Fengling ◽  
Li Duolu ◽  
Dai Rensong ◽  
Xu Xurong
Keyword(s):  
Band Edge ◽  
Band Edge Emission ◽  
Dispersion Theory ◽  
Edge Emission

Enhancement of Photoluminescence from Organic and Inorganic Surface Passivated ZnS Quantum Dots

2001 ◽  
Vol 667 ◽  
Author(s):  
Hatim Mohamed El-Khair ◽  
Ling Xu ◽  
Mingha Li ◽  
Yi Ma ◽  
Xinfan Huang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Organic Coating ◽  
Band Edge ◽  
Band Edge Emission ◽  
Trap States ◽  
Edge Enhancement ◽  
Edge Emission ◽  
Inorganic And Organic

ABSTRACTZnS quantum dots (QDs) chemically synthesized in PVP stabilizing medium have been coated with Zn(OH)2, SiO2and polystyrene (PS) shells as inorganic and organic passivation agents. to synthesize ZnS/Zn(OH)2, ZnS/SiO2and ZnS/PS QDs. PL properties of inorganically passivated ZnS/Zn(OH)2 and ZnS/SiO2 had reported band edge enhancement of 8-10 times, while organically passivated ZnS/PS QDs exhibit tremendous enhancement of band edge emission as much as 10-15 times,. Therefore inorganic and organic coating can passivate trap states of different energies on the surface of ZnS QDs.

Enhancement of the near-band-edge emission of CuI by Cl doping

2019 ◽  
Vol 205 ◽  
pp. 337-341 ◽  
Author(s):  
Fengrui Li ◽  
Mu Gu ◽  
Xiaolin Liu ◽  
Shuangqiang Yue ◽  
Jiajie Zhu ◽  
...  
Keyword(s):  
Band Edge ◽  
Near Band Edge Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Edge Emission

Band-edge emission, defects, morphology and structure of in-doped ZnO nanocrystal films

2019 ◽  
Vol 89 ◽  
pp. 322-328 ◽  
Author(s):  
B. El Filali ◽  
J.A. Jaramillo Gomez ◽  
T.V. Torchynska ◽  
J.L. Casas Espinola ◽  
L. Shcherbyna
Keyword(s):  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Morphology And Structure ◽  
Nanocrystal Films ◽  
Doped Zno ◽  
Zno Nanocrystal
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