The vacancy-type defects in (Ga,Mn)N films grown by metal organic chemical vapor deposition were studied by positron annihilation technique. Doppler broadening spectra were measured for the films. Compared to the undoped GaN film, the positron trapping defects in the (Ga,Mn)N films have been changed to a new type defects and its concentration increases with the increasing Mn concentration. By analyzing the S-W correlation plots and our previous results, we identify this type defects in the (Ga,Mn)N as VN-MnGa complex. This type of defects should be considered when understand the magnetic properties in a real (Ga,Mn)N system.

In order to measure the thermal emission rate of a trap in semiconductor material without scanning the temperature, a new method, which utilizes a spectrum analyzer, has been developed. The theory on which our measuements depend is based on the relation between the time constant of a pure exponential wave and the relative amplitudes of its Fourier Components. The time constant is given by ts = (t/2r)[(10c−1)/(m2−10cn2)]1/2, where c = (Xn−xm/10, t is the period of the exponential wave, and xn and xm are the amplitudes of the nth and mth harmonics in dB, respectively.