Ferromagnetism and p-type Conductivity in Laser-deposited (Zn,Mn)O Thin Films Codoped by Mg and P

We report on the observation of p-type conductivity and ferromagnetism in diluted magnetic semiconductor (Zn 0.97 Mg 0.01 Mn 0.02 )O:P films grown on SiO₂/Si substrates by pulsed laser deposition. The p-type conduction with hole concentration over 1018 ㎝ ?3 is obtained by codoping of Mg and P followed by rapid thermal annealing in an O₂atmosphere. Structural and compositional analyses for the p-type (Zn 0.97 Mg 0.01 Mn 0.02 )O:P films annealed at 800 ℃ indicates that highly c-axis oriented homogeneous films were grown without any detectable formation of secondary phases. The films were found to be transparent in the visible range. The magnetic measurements clearly revealed an enhancement of room temperature ferromagnetism by p-type doping.