Optically Detected Magnetic Resonance and Double Beam Photoluminescence of CdS/HgS/CdS Nanoparticles

1998 ◽  
Vol 536 ◽  
Author(s):  
H. Porteanu ◽  
A. Glozman ◽  
E. Lifshitz ◽  
A. Eychmüller ◽  
H. Weller
Keyword(s):  
Optical Properties ◽  
Magnetic Resonance ◽  
Cds Nanoparticles ◽  
Electron Hole ◽  
Cladding Layer ◽  
Double Beam ◽  
Optically Detected Magnetic Resonance ◽  
Optically Detected ◽  
Cladding Layers ◽  
Hole Recombination

AbstractCdS/HgS/CdS nanoparticles consist of a CdS core, epitaxially covered by one or two monolayers of HgS and additional cladding layers of CdS. The present paper describes our efforts to identify the influence of CdS/HgS/CdS interfaces on the localization of the photogenerated carriers deduced from the magneto-optical properties of the materials. These were investigated by the utilization of optically detected magnetic resonance (ODMR) and double-beam photoluminescence spectroscopy. A photoluminescence (PL) spectrum of the studied material, consists of a dominant exciton located at the HgS layer, and additional non-excitonic band, presumably corresponding to the recombination of trapped carriers at the interface. The latter band can be attenuated using an additional red excitation. The ODMR measurements show the existence of two kinds of electron-hole recombination. These electron-hole pairs maybe trapped either at a twin packing of a CdS/HgS interface, or at an edge dislocation of an epitaxial HgS or a CdS cladding layer.

Continuous and Time Resolved Optically Detected Magnetic Resonance Studies of InP Nanoparticles

2001 ◽  
Vol 692 ◽  
Author(s):  
L. Langof ◽  
E. Ehrenfreund ◽  
E. Lifshitz ◽  
O. I. Micic ◽  
A. J. Nozik
Keyword(s):  
Magnetic Resonance ◽  
Hole Pair ◽  
Resonance Spectroscopy ◽  
Electron Hole ◽  
Time Resolved ◽  
Defect Emission ◽  
Optically Detected Magnetic Resonance ◽  
Electron Hole Pair ◽  
Optically Detected ◽  
Defect Luminescence

AbstractCarriers in small colloidal InP nanoparticles are in strong quantum confinement regime. The low temperature photoluminescence spectrum of InP nanoparticles is composed of an excitonic luminescence at high energies and a non-excitonic defect emission band at lower energies. HF etching of the nanoparticles reduces the defect emission and enhances the exciton process.In this work we apply optically detected magnetic resonance spectroscopy (ODMR) both in continuous wave and time resolved mode (TR-ODMR) to study the defect luminescence in InP nanoparticles. The results show that the defect luminescence originates from weakly coupled electron-hole pair, where the electron is trapped at the surface by phosphorous vacancy, Vp, and the hole is located at the valence band. Additionally, the results suggest that the non-etched samples are dominated by Vp at the surface. Those are mainly eliminated upon HF treatment, leaving behind small percent of Vp in the core of the nanoparticle. We also find the electron-hole exchange interaction from circular polarized ODMR measurements. The TR-ODMR measurement further clarifies the spin dynamics and characteristic of the magnetic sites. Fitting these measurements to the simulated response of the PL intensity to the square wave modulated microwave power revealed that the spin relaxation time and radiative lifetime of electron-hole pair in the nanoparticles are in the microseconds regime.

Optical and Magnetic Resonance Investigations of Mercuric Iodide Crystals

1992 ◽  
Vol 242 ◽  
Author(s):  
B.K. Meyer ◽  
D.M. Hofmann ◽  
J. Eckstein ◽  
K.W. Benz
Keyword(s):  
Optical Properties ◽  
Circular Dichroism ◽  
Magnetic Resonance ◽  
Optical Absorption ◽  
Magnetic Circular Dichroism ◽  
Energy Levels ◽  
Mercuric Iodide ◽  
Optically Detected Magnetic Resonance ◽  
Optically Detected ◽  
Circular Dichroïsm

ABSTRACTThe optical properties of the red modification of mercuric iodide (HgJ2) were studied by optical absorption, magnetic circular dichroism, photoluminescence and optically detected magnetic resonance investigations. The experiments demonstrate the involvment of acceptors with energy levels at Ev + 0.14 ± 0.01 eV and 0.15 ± 0.01 eV in the absorption and recombination at 2.2 eV. The g - values are 0.85 and 0.74, respectively.

Optically detected magnetic resonance study of SiC:Ti

1985 ◽  
Vol 32 (4) ◽  
pp. 2273-2284 ◽  
Author(s):  
K. M. Lee ◽  
Le Si Dang ◽  
G. D. Watkins ◽  
W. J. Choyke
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Study ◽  
Optically Detected Magnetic Resonance ◽  
Optically Detected
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