Electrical properties of amorphous chalcogenide/silicon heterojunctions modified by ion implantation

• Main Authors: Hewak, Dan W., Fedorenko, Yanina G., Lee, Tae-Hoon, Hughes, Mark A., Colaux, Julien L., Jeynes, C., Gwilliam, Russell M., Homewood, Kevin P., Yao, Jin, Elliott, Stephen R., Gholipour, B., Curry, Richard J.
• Other Authors: Digonnet, Michel J. F.
• Format: Conference or Workshop Item
• Language: English
• Published: 2014
• Subjects: DRNTU::Science
• Online Access: https://hdl.handle.net/10356/100033; http://hdl.handle.net/10220/19677
• Institution: Nanyang Technological University

Doping of amorphous chalcogenide films of rather dissimilar bonding type and resistivity, namely, Ga-La-S, GeTe, and Ge-Sb-Te by means of ion implantation of bismuth is considered. To characterize defects induced by ionbeam implantation space-charge-limited conduction and capacitance-voltage characteristics of amorphous chalcogenide/silicon heterojunctions are investigated. It is shown that ion implantation introduces substantial defect densities in the films and their interfaces with silicon. This comes along with a gradual decrease in the resistivity and the thermopower coefficient. It is shown that conductivity in GeTe and Ge-Sb-Te films is consistent with the two-type carrier conduction model. It is anticipated that ion implantation renders electrons to become less localized than holes leading to electron conductivity in certain cases as, for example, in GeTe.