Study Of Ferromagnetic Stability Of P-n Codoped Diluted Magnetic Semiconductor

Diluted magnetic semiconductors (DMSs) are introduced on thebasis of conventional semiconductor with electronic spin property,which makes it have more extensive application prospects in thefield of microelectronics. But there are some important unsolvedproblems, such as magnetic mechanism， low Curie temperature,codopant dissolved solid solubility, etc. This study systematicallyresearch the effect of p-n codoping method on the ferromagneticstability in some diluted magnetic semiconductor systems. Andthen we found the general law of improvement of Curie temperature.The specific research includes the following two sections:(1) we study of electronic structure and magnetic properties ofp-n codoped ZnO and Ge using first principles density functionaltheory. It shows that the electro negativity and atomic radius of acodopant have great influence of ferromagnetic stability in ZnO andGe based DMS. In detail, we calculated of electronic structures andmagnetic properties in Mn/Se, Mn， As， Mn/Al， Mn/Ga， Mn/P， Mn/Scodoped ZnO and Ge base DMS. We find that the electro negativityand ionic radius of codopant can influence ferromagnetic stabilityand they play an important role. In the periodic table of the sameperiod, the larger of the electro negativity, the more stable of theferromagnetic state. If the ionic radius is smaller, the stability of the ferromagnetic is the greater. These findings will provide a goodway to improve the Curie temperature for Ge and ZnO based DMSspin devices.(2) We study of structure and magnetic properties of GaAsbased DMS using the first principles density functional calculations.Our results show that ferromagnetic stability of p-p codoped GaAsis weaker than Mn doped GaAs. However, ferromagnetic stability ofp-n codoped GaAs will be stronger than Mn doped GaAs. Therefore,p-n codoping method will increase the Curie temperature of GaAsbased DMS. Our results show that the Curie temperature of Mn/Siand Mn/Ge codoped GaAs based DMS(p-n codoping) will beimproved.