PL
 |
EN
Ten serwis zostanie wyłączony 2025-02-11.
Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 16

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote Photoelectronic Processes in ZnSe:Cu Single Crystals
100%
Firszt F.
Acta Physica Polonica A
|
1992
|
tom 82
|
nr 5
893-895
EN
Measurements of steady state and transient stimulation and quenching of photocurrent and luminescence were performed in ZnSe single crystals doped with Cu which exhibit marked change in the photoconductivity and luminescence when illuminated by infrared light simultaneously with shorter wavelength radiation. A model which might explain all IR induced phenomena on the basis of donor-acceptor pair recombination mechanism including releasing holes from deep center by IR light and energy redistribution between different recombination centers is presented.
2
Content available remote Exciton Electroluminescence of ZnSe/ZnO Structures under Biaxial Stress
51%
Bała W. , Firszt F. , Łęgowski S. , Męczyńska H.
Acta Physica Polonica A
|
1992
|
tom 82
|
nr 5
896-899
EN
The strained ZnSe/ZnO structures grown on (111) ZnSe crystals by plasma oxidation was investigated by electro- and photoluminescence methods. The lines of heavy and light hole excitons under biaxial compressive stress are measured as a function of the temperature.
3
Content available remote Electrical and Optical Properties of ZnSe:Mg Crystals
51%
Szatkowski J. , Firszt F. , Męczyńska H. , Łęgowski S.
Acta Physica Polonica A
|
1993
|
tom 84
|
nr 3
531-534
EN
ZnMgSe mixed crystals were obtained by the high pressure Bridgman method and by thermal diffusion of Mg metal into ZnSe crystals. Measurements of luminescence and transmission spectra show that the band-gap energy of such mixed crystals is larger than that of "pure" ZnSe. ZnMgSe crystals exhibit n-type conductivity and electrical parameters comparable with that of ZnSe. Blue-violet luminescence in the temperature range from 40 K to room temperature was observed. This feature makes this material very promising for future applications in constructing short wavelength electroluminescent devices.
4
Content available remote Optical and Electrical Properties of Iodine Doped n-Type ZnSe Crystals
51%
Balcerzyk M. , Firszt F. , Męczyńska H.
Acta Physica Polonica A
|
1991
|
tom 79
|
nr 2-3
299-302
EN
We have studied the electrooptical properties of ZnSe single crystals doped with iodine by diffusion at high temperature. The obtained samples are highly conductive. The luminescence at 300 K (RT) is dominated by well known self activated orange emission. At 30 K the blue and orange emission is observed. The ratio of the blue emission peak intensity to the deep level one is much greater for the iodine doped samples than for the undoped intentionally ones.
5
Content available remote Luminescence of Zn_{x}Mg_{1-x}Se Layers Obtained by Thermal Diffusion of Mg into ZnSe and Zn_{x}Mg_{1-x}Se Epilayers Grown by Molecular Beam Epitaxy
45%
Bała W. , Firszt F. , Głowacki G. , Gapiński A. , Dzik J.
Acta Physica Polonica A
|
1995
|
tom 87
|
nr 1
161-164
EN
This work deals with the study of photoluminescence properties of Zn_{x}Mg_{1-x}Se epilayers grown by molecular beam epitaxy on (001) GaAs and (111) ZnTe substrates and Zn_{x}Mg_{1-x}Se layers obtained by thermal diffusion of Mg into ZnSe single crystals. Luminescence spectra of Zn_{x}Mg_{1-x}Se layers are dominated by blue and violet emission bands with maxima positioned in the range of photon energies: 3.05-3.28 eV, 2.88-3.04 eV, 2.81 eV and 2.705 eV, depending on preparation conditions. In some samples the blue luminescence is observed up to room temperature.
6
Content available remote Transient Photo-Induced Current Measurements in High Resistivity ZnSe Crystals
45%
Bała W. , Firszt F. , Dul D. , Turlo Z. , Borkowski J.
Acta Physica Polonica A
|
1991
|
tom 79
|
nr 2-3
295-298
EN
Using technique of computerized signal-averaging of photocurrent transient, we have studied the details of deep level states in high resistivity ZnSe crystals. The time resolved spectra of photocurrent and four-gate PICT spectra are presented.
7
Content available remote Photoacoustic Investigation of Absorption Edge of Cd_{1-x}Mg_{x}Se Mixed Crystals
38%
Firszt F. , Łęgowski S. , Męczyńska H. , Sekulska B. , Szatkowski J. , Zakrzewski J. , Paszkowicz W.
Acta Physica Polonica A
|
1997
|
tom 92
|
nr 4
749-752
EN
The Cd_{1-x}Mg_{x}Se crystals were grown by modified Bridgman method for x ranging from 0 to 0.44. The photoacoustic spectroscopy was employed for evaluation of the band gaps of series Cd_{1-x}Mg_{x}Se mixed crystals with different composition. The photoacoustic spectra were measured at 300 K and 90 K using continuous wave excitation in the range from 400 nm to 800 nm. The increase in the band-gap energy with increasing Mg content is observed. The photoacoustic results are compared with photoluminescence and transmission spectra.
8
Content available remote Composition Dependence of Photoluminescence Spectra in Zn_{1-x}Mg_{x}Se Mixed Crystals
38%
Firszt F. , Łęgowski S. , Μęczyńska H. , Szatkowski J. , Paszkowicz W. , Spolnik Z. M.
Acta Physica Polonica A
|
1995
|
tom 88
|
nr 4
711-714
EN
Ζn_{1-x}Mg_{x}Se mixed crystals with x ranging from 0 to 0.56 were obtained by high pressure Bridgman method. It has been found that a phase transition from sphalerite structure to wurtzite one occurs at x = 0.185 ± 0.03. The crystals exhibit blue-violet and yellow-green (depending on x) luminescence in the temperature range from 40 K to room temperature. An attempt has been also made to dope Ζn_{1-x}Μg_{x}Se crystals with Al. The incorporation of Al produces a strong green photoluminescence in the temperature range from 40 K to 300 K but almost completely quenches the near-band-edge emission.
9
Content available remote Visible Luminescence from Porous Silicon
38%
Bała W. , Firszt F. , Nossarzewska-Orłowska E. , Brzozowski A. , Orłowski B. , Kowalski B. , Guziewicz E.
Acta Physica Polonica A
|
1993
|
tom 84
|
nr 4
761-764
EN
This paper presents results of investigation of the temperature dependence of visible luminescence in porous silicon layers prepared by anodization in hydrofluoric acid. Luminescence spectra were measured in the temperature range between 40 K and 350 K. Room temperature reflectivity spectra were also measured in vacuum ultraviolet radiation range from 4 eV to 12 eV.
10
Content available remote Photoluminescence and Photoacoustic Investigations of Beryllium and Magnesium Containing Wide Gap II-VI Mixed Crystals
38%
Firszt F. , Łęgowski S. , Męczyńska H. , Sekulska B. , Szatkowski J. , Zakrzewski J. , Paszkowicz W.
Acta Physica Polonica A
|
1999
|
tom 95
|
nr 6
991-996
EN
Zn_{1-x}Be_{x}Se, Cd_{1-x}Mg_{x}Se and Zn_{1-x-y}Be_{x}Mg_{y}Se mixed crystals grown from the melt with different concentrations of Be and Mg have been characterized by photoluminescence and photoacoustic methods. An increase in band gap energy with increasing Be and Mg contents was observed. The photoacoustic spectroscopy was also employed for evaluation of thermal diffusivity of mixed Zn_{1-x}Be_{x}Se crystals with different beryllium contents.
11
Content available remote Cathodoluminescence Studies of Polytype Structure in Zn_{1-x}Mg_{x}Se
38%
Cichos A. , Firszt F. , Falke U. , Lenzner J. , Męczyńska H. , Hietschold M.
Acta Physica Polonica A
|
1999
|
tom 95
|
nr 2
269-274
EN
Zn_{1-x}Mg_{x}Se crystals grown by Bridgman method show spatial transition from sphalerite (3C) to wurzite structure (2H) with increasing Mg content (x). Within the transition range, near x=0.19, coexistence of hexagonal and cubic structure results in the formation of polytype sequences of 3C-8H-4H-2H. We have investigated the spatial distribution of the polytypes in Zn_{1-x}Mg_{x}Se mixed crystals with a value of x close to that of the phase transition using spectrally as well as spatially resolved cathodoluminescence. Three emission bands in the cathodoluminescence spectrum have been observed, two strong lines at 2.99 eV and 2.965 eV, and a weak shoulder at 2.95 eV. The lines at 2.965 and 2.99 eV are known in the literature as an exciton recombination in the 8H and 4H polytype structure. We have found the third one at 2.95 eV to be due to luminescence in the 3C structure. These results demonstrate the usefulness of cathodoluminescence measurements for investigations of spatial distribution of inhomogeneities of mixed semiconductors.
12
Content available remote Optical and Structural Properties of Zn_{1-x}Be_{x}Se Mixed Crystals
32%
Firszt F. , Łęgowski S. , Męczyńska H. , Szatkowski J. , Zakrzewski J. , Paszkowicz W. , Domagała J. , Marczak M.
Acta Physica Polonica A
|
1998
|
tom 94
|
nr 2
309-312
EN
Optical and structural properties of Zn_{1-x}Be_{x}Se bulk crystals in the range of composition 0 ≤ x ≤ 0.41 have been studied. These crystals were grown by Bridgman method under an argon overpressure. Transmission, absorption, photoluminescence and photoacoustic spectra as a function of composition were investigated. It has been found that the crystal structure is of sphalerite type. The crystal quality increases when the crystallization process of the same boule is performed more than once. In the investigated composition range the lattice constant decreases and the energy gap increases with increasing beryllium content. From photoluminescence measurements the excitonic energy gap about 3.64 eV at 40 K was estimated for the highest obtained Be concentration (x=0.41).
13
Content available remote Positron Annihilation Characteristics in Zn_{1-x}Mg_{x}Se Mixed Crystals
32%
Firszt F. , Szatkowski J. , Męczyńska H. , Łęgowski S. , Saarinen K. , Hautojarvi P. , Plazaola A. , Reniewicz H. , Dobrzyński L. , Chabik S.
Acta Physica Polonica A
|
1998
|
tom 94
|
nr 2
300-304
EN
Positron annihilation characteristics as a function of composition and annealing in zinc vapour were measured and compared with photoluminescence spectra for Zn_{1-x}Mg_{x}Se mixed crystals with 0 ≤ x ≤ 0.6. The positron annihilation data show that there is a substantial number of divacancies present in the system under study. The concentration of such defects is reduced at least by the factor of two upon annealing in zinc vapour.
14
Content available remote Raman Scattering in Zn_{1-x}Mg_{x}Se Mixed Crystals
32%
Kozielski M. , Szybowicz M. , Firszt F. , Łęgowski S. , Męczyńska H. , Sekulska B. , Szatkowski J. , Paszkowicz W.
Acta Physica Polonica A
|
1996
|
tom 90
|
nr 5
1040-1044
EN
This paper presents results of investigations of the Raman scattering of vibrational modes in Zn_{1-x}Mg_{x}Se crystals for the range of composition 0 < x < 0.43. The Raman polarized spectra of Zn_{1-x}Mg_{x}Se were measured at room temperature. The typical Raman spectrum shows four peaks which can be interpreted as longitudinal and transverse optical ZnSe-like and MgSe-like phonons. The ZnSe-like and MgSe-like vibrations can be described by the modified random element isodisplacement model. Results of the Raman measurements in the investigated range of composition confirm the two-mode behaviour of the optical phonons in the mixed Zn_{1-x}Mg_{x} Se crystals.
15
Content available remote Investigation of Electronic Structure of Zn_{1-x}Mg_{x} Mixed Crystals by Compton Spectroscopy Method
32%
Reniewicz H. , Andrejczuk A. , Dobrzyński L. , Rećko K. , Waliszewski J. , Żukowski E. , Firszt F. , Łęgowski S. , Meczyńska H. , Szatkowski J.
Acta Physica Polonica A
|
1996
|
tom 90
|
nr 5
907-910
EN
The first experimental study of the Compton profiles of Zn_{1-x}Mg_{x}Se for x=0.25, 0.47, 0.56 mixed crystals is presented. The Compton profiles were measured with the use of the ^{241}Am radioactive source with a resolution of 0.57 a.u. The experimentally obtained Compton profiles were compared with the theoretical ones based on the free-atom model. The results are interpreted in terms of outermost electrons of Zn and Mg being promoted to the higher momentum states, and 4p-electrons of Se becoming more delocalised in a solid, being thus promoted to the lower momentum states.
16
Content available remote A Photoacoustic Study of Zn_{1-x}Mg_{x}Se Mixed Crystals
32%
Męczyńska H. , Zakrzewski J. , Łęgowski S. , Popielarski M. , Firszt F. , Szatkowski J. , Klugiewicz R. , Łęgowski K.
Acta Physica Polonica A
|
1995
|
tom 87
|
nr 2
547-550
EN
The photoacoustic spectroscopy with a piezoelectric transducer was em­ployed to evaluate the band gaps of a series of Zn_{1-x}Mg_{x}Se mixed crystals of different composition. The photoacoustic measurements performed at room temperature yield information about the quality of the samples. The photoa­coustic spectra were measured using the continuous wave and nanosecond pulse excitation.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.