Synthesis and optical properties of Cl-doped ZnS nanoribbons

ZnS is an important semiconductor for a number of applications. It is a promising triboluminescence material, especially for UV light-emitting diodes (LEDs) and laser diodes (LDs), because of the direct and wide bandgap of 3.77 eV, and a relatively large exciton binding energy (~40meV) for the hexagonal wurtzite phase at room temperature. The ion doping can cause intense fluorescence and persistent phosphorescence in ZnS nanostructures. Cl-doped wurtzite ZnS nanoribbons on Au-coated Si wafers have been successfully synthesized through a chemical vapor deposition based on the vapor-liquid-solid (VLS) mechanism. Co-dopant Cl-1 ions can serve as donors, producing a donor-acceptor pair transition with the ZnS valence band level. Photoluminescence and cathodoluminescence were used to study the optical properties of Cl-doped ZnS nanoribbons. Compared with the undoped counterpart, the blue emission peak at 2.78 eV was observed due to the co-dopant Cl-1 luminescence centers, which indicates its potential applications in visible light-emitting diodes, photodetectors and also some applications in transport properties.