Doping of II-VI Semiconductors

• Applicant: Professor Dr. Thomas Wichert
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2000 to 2003
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5259442

The majority of II-VI semiconductors can only be doped with high efficiency either p- or n-type. The availability of both types of electrical carriers, however, is of fundamental importance to most electronic devices. Moreover, the doping procedure itself turns out to be more complicated in these materials than in Si; for example doping by ion implantation, a technique being central to Si technology, is very difficult to achieve. In this proposal, the incorporation of electrically active dopants in II-VI semiconductors will be studied: p-type doping of ZnSe and n-type doping of ZnTe; doping by ion implantation; dopant-hydrogen interactions; and influence of residual impurities. For investigating the incorporation of dopant atoms and their interactions with intrinsic and extrinsic defects, the perturbed gg angular correlation technique (PAC) and the photoluminescence spectroscopy (PL) using the following radioactive isotopes will be applied: 77Br, 111In, and 111Ag (PAC) and 67Cu, 67Ga, 71As, 77Br, 111Ag, and 131I (PL). Theoretical calculations of defect induced electric field gradients (efg) will support the interpretation of the efg measured by PAC. The implantation of the radioactive isotopes offers the control of purity, depth distribution, and dose, which is decisive for the interpretation of the obtained experimental information and, finally, offers access to the study of the implantation process itself.

• DFG Programme: Research Grants