Search results

1

Luminescence of Cu^{+} and Cu^{2+} Ions in CsBr Crystals

100%

Zorenko Y., Voznyak T., Turchak R.

|

issue 1

199-202

EN

The luminescence of Cu^{+} and Cu^{2+} ions in CsBr:Cu and CsBr:CuBr_{2} crystals, respectively, is investigated under excitation by synchrotron radiation in the CsBr fundamental absorption range at 10 K and 300 K. The existence of the luminescence bands of different origin: (i) the intrinsic radiative transition of Cu^{+} ions in the bands peaked at 2.61 eV and 2.23 eV, (ii) the recombination luminescence of Cu^{2+} ions in the bands peaked at 2.55 eV and 2.13 eV, (iii) the luminescence of excitons localized around Cu^{+} and Cu^{2+} ions in the band peaked at 3.08 eV and 3.38 eV, respectively, was found in CsBr:Cu and CsBr:CuBr_{2} crystals. The energies of creation of exciton localized around Cu^{+} and Cu^{2+} ions (6.06 eV and 6.09 eV, respectively, at 10 K) and excitons bound with these ions (5.83 eV and 5.99 eV at 300 K) were determined as well.

2

Pulsed EPR and ENDOR Study of SiC Nanopowders

100%

Savchenko D.

|

vol. 126

|

issue 5

1063-1065

EN

In this work field-sweep electron spin echo and pulsed electron nuclear double resonance study of the silicon carbide (SiC) nanoparticles (np-SiC) of different sizes is presented. Nitrogen (N) triplet lines due to the isolated N donor state was observed in np-SiC with grain size d>100 nm. With a decrease of the particle size up to 50 nm the N triplet lines transforms into one single exchange line due to the delocalization of the donor wave function caused by the size confinement effect. Along with N donors the carbon vacancy (V_{C}) located in cubic phase was observed in np-SiC with d < 100 nm. The further decrease of the grain size to d < 50 nm leads to the appearance of the V_{C} located in hexagonal crystalline phase and carbon dangling bonds located in the carbon excess phase of np-SiC. The fact that only N donor center at "k2" quasi-cubic position substituting Si site was observed in the field-sweep electron spin echo and pulsed electron nuclear double resonance spectra of np-SiC was explained by high compensation degree of the samples and the presence of carbon excess in np-SiC. The appearance of the proton electron nuclear double resonance signal in no-SiC with d < 100 nm indicates that the hydrogen retention in np-SiC increases with decreasing of grain size.

3

Paramagnetic State of Hydrogen-Passivated Double-Donor Centers in Silicon

100%

Gregorkiewicz T., Zevenbergen I., Martynov Y., Ammerlaan C.

Acta Physica Polonica A

|

1995

|

vol. 88

|

issue 4

735-738

EN

Hydrogenation of two double donor centers in silicon - substitutional sulfur and thermal donor - is studied by electron paramagnetic resonance and electron-nuclear double resonance. For both centers the existence of a new paramagnetic S = 1/2 state identified as the neutral charge state of the double donor passivated with a single hydrogen atom is concluded. The microscopic structure of such complexes is discussed.

Refine search results

3 Acta Physica Polonica A

1 2014

1 2010

1 1995

1 Ammerlaan C.

1 Gregorkiewicz T.

1 Martynov Y.

1 Savchenko D.

1 Turchak R.

1 Voznyak T.

1 Zevenbergen I.

1 Zorenko Y.

Luminescence of Cu^{+} and Cu^{2+} Ions in CsBr Crystals

Pulsed EPR and ENDOR Study of SiC Nanopowders

Paramagnetic State of Hydrogen-Passivated Double-Donor Centers in Silicon