RESUMEN
A lithium and nitrogen codoping method has been employed to prepare p-type MgZnO films, and p-MgZnO/i-ZnO/n-ZnO structured light-emitting devices (LEDs) and photodetectors have been fabricated. The LEDs can work continuously for about 97 h under the injection of a 20 mA continuous current, which is the best value ever reported for ZnO-based LEDs. The performance of the photodetectors degrades little after several running cycles. The above results reveal the applicability of the p-MgZnO films in optoelectronic devices.
RESUMEN
Systematic magnetic, electronic, and electrical studies on the Cu0.04Zn0.96O/Ga0.01Zn0.99O cell structure grown on (001) sapphire by the pulsed laser deposition technique show that the Cu multivalent (CuM+) ions modulate magnetic and resistive states of the cells. The magnetic moment is found to be reduced by â¼30% during the high resistance state (HRS) to low resistance state (LRS) switching. X-ray photoelectron spectroscopy results reveals an increase of the Cu+/Cu2+ oxidation state ratio (which has been determined by the relative positions of the Fermi level and the Cu acceptor level) during the HRS to LRS transition. This decreases the effective spin-polarized Cu2+-Vö-Cu+ channels and thus the magnetic moment. A conduction mechanism involving the formation of conductive filaments from the coupling of the CuM+ ions and Vö has been suggested.