OPTICAL AND ELECTRICAL PROPERTIES OF Zn1−xBexSe GROWN BY MOLECULAR BEAM EPITAXY
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Дата
2004
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Анотація
The dopant behaviour in the n-type ZnBeSe:Cl and p-type ZnBeSe:N grown by Molecular Beam Epitaxy (MBE)is investigated.All the samples have been grown on (001)GaAs substrates
(conducting or semi-insulating).For the experimental investigation the photoluminescence(PL),Raman Scattering, photoconductivity and I–V measurements are used.From the temperature(9 K–300 K)and exitation intensity dependent on PL measurements it will be shown that donor and acceptor impurities exhibit a somewhat different behaviour and/or properties from those in ZnSe.We argue that(i)the activation energy of both the N acceptor and Cl donor increases in ZnBeSe as concentration
of Be increases;(ii) all the indoped and n-type samples exhibit high (>180 K) temperature PL associated with shallow impurity of acceptor type, which also show an increase in the binding energy with Be
composition;Raman scattering experiments have shown that at low Be concentrations (x < 0.04)one can use LO photon energy in ZnSe in the analyses of PL spectra from ZnBeSe.
From photoconductivity and I–V measurements we show that(i) there are a number of carrier traps in ZnBeSe:Cl;(ii) some of the ZnBeSe samples with Be concentrations over 1% exhibit photoconductivity behaviour associated with the presence of DX centres or other deep trap, i. e., we observe persistent photoconductivity;(iii) volt-ampere dependencies (with and without irradiation)are different for the samples grown on conducting and semi-insulating substrates.
Опис
Журнал фiзичних дослiджень = Journal of Physical Studies. - Львiв : Б.в.
Ключові слова
molecular beam epitaxy, dopant behaviour, photoluminescence, Raman Scattering, photoconductivity, activation energy, donor, acceptor, carrier, trap, photon, volt-ampere dependence
Бібліографічний опис
Журнал фiзичних дослiджень = Journal of Physical Studies