Studies of electrical and optoelectronic properties of Ge-ion-implanted SiO2 thin films

Abstract

This thesis presents a systematic investigation on the electrical and optoelectronic properties of SiO2 thin films embedded with Ge nanocrystals (nc-Ge) synthesized by the low-energy ion implantation technique for the applications in non-volatile memories and light-emitting devices. First of all, different conduction mechanisms dominating in different oxide field regions are investigated from the current transport behaviors. Besides, the effect of conduction modulation caused by the charging / discharging of nc-Ge is reported. After that, the charge trapping and charge retention behaviors of Ge-ion-implanted SiO2 thin films are studied in details. Furthermore, by taking into account of the nc-Ge distribution as well as the suppressed dielectric constant of nc-Ge, an approach to calculate the capacitances of Ge-ion-implanted SiO2 thin films is presented. Lastly, the visible electroluminescence (EL) from light-emitting devices based on Ge-ion-implanted SiO2 thin film is presented. The enhancement of EL intensity with implant energy and dose is also investigated.