CHLORINE - A NEW EFFICIENT NORMAL-TYPE DOPANT IN CDTE LAYERS GROWN BY MOLECULAR-BEAM EPITAXY

We report for the first time on successful n-type doping of CdTe epilayers by the use of chlorine. The free-carrier concentration in the layers, grown by molecular beam epitaxy (MBE) and photoassisted MBE, can be varied easily over three orders of magnitude by changing the ZnCl2 oven temperature. Peak mobilities between 4700 cm2/Vs (n = 1.8 X 10(16) cm-3) and 480 cm2/V s (n = 1.6 X 10(18) cm-3) are obtained. The resistivity of highly Cl-doped layers is as low as 8.5 X 10(-3) OMEGA CM. Compared with In, which is commonly used for obtaining n-type CdTe epilayers, higher free-carrier concentrations and higher peak mobilities are obtained for compatible growth procedures by the use of Cl.