Highhyphen;qualitynhyphen;type ZnSe layers have been grown by molecularhyphen;beam epitaxy using chlorine (Cl) as a dopant. The Clhyphen;doped ZnSe layers showed mirrorlike morphology and good crystallinity, although some degrade in crystallinity is observed at a heavy doping. The carrier concentration of the layer could be widely controlled by a ZnCl2Knudsen cell temperature. The carrier concentration attained 1times;1019cmminus;3, where the resistivity was as low as 3times;10minus;3OHgr;thinsp;cm, indicating a remarkable improvement compared to the previous work using grouphyphen;III elements as a dopant. Hall mobilities at room temperature were in the range of 200ndash;400 cm2/(Vthinsp;s), depending on the doping level. The Clhyphen;doped ZnSe layer exhibited strong blue nearhyphen;bandhyphen;gap photoluminescence (PL) with suppressed deephyphen;level emission at room temperature. The 4.2hyphen;K PL of the layer was dominated by strong emission of excitons bound to neutral donors originating from substitutional Cl atoms. It was found by a secondary ionhyphen;masshyphen;spectroscopy analysis that diffusion of Cl atoms in the ZnSe layer during growth was negligible (370 Aring;).
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