Magnetoluminescence study of n-type modulation-doped ZnSe/ZnxCd1

Γ. Κιοσέογλου

¹

,

J. Haetty

²

,

H. C. Chang

³

et al.

Magneto-optics of two-dimensional electron gases modified by strong Coulomb interactions in ZnSe quantum wells

“…The Coulomb energy amounts to 30-40 meV. In earlier studies of n-type doped (Zn,Cd)Se/ZnSe QWs the well layers were made of ternary alloy (Zn,Cd)Se [25,26,27]. This results in a considerable broadening of optical lines by alloy fluctuations which obscures fine details in the spectroscopic analysis.…”

“…the exciton binding energy in bulk ZnSe is 20 meV). Modification of the optical spectra of modulation-doped quantum wells (QW) containing a 2DEG has been the subject of extensive theoretical [2,3,4,5,6,7,8,9,10] and experimental studies [11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27].…”

Optical and structural studies of the effect of spacers in modulation-doped ZnSe/Zn1−xCdxSe quantum wells

“…The large linewidth of the PL peak, which is a quantum well band-edge emission, is the result of the two-dimensional electron gas and has been reported elsewhere. 5 At 10 K, the full width at half maximum ͑FWHM͒ of the as-grown structure without a spacer ͑39 meV͒ is more than twice as broad as that with spacers ͑16 meV͒. The asymmetric line shape persists up to 70 K. Similar asymmetric line shapes were reported in several III-V and II-VI MD-MQWs such as In 1Ϫx Ga x As/InP:S 7 and Cd 1Ϫx Mn x Te:In/CdTe.…”

“…The growth temperature for both samples was kept at 300°C, and the growth conditions are the same as those used in other modulation-doped Zn 1Ϫx Cd x Se/ZnSe quantum well structures previously reported. 5 The diffusion was studied by thermal annealing at 250, 320, and 385°C with 30 min of annealing time. The samples with and without spacers were simultaneously annealed at the same condition to minimize experimental fluctuation.…”

“…Spacers have been commonly used in modulationdoped multiple quantum wells to suppress dopant migration and the effect of ionized donors in barriers on twodimensional electron gas in quantum wells. Since ZnCdSe/ ZnSe:Cl MD-MQW structures are relatively new structures, 5 very little is known about the role of spacers, particularly in connection with thermal treatment. In this article, we focus on the thermal behavior in ZnCdSe/ZnSe:Cl MD-MQW structures, especially for the effect of spacers.…”