The electrical and optical characteristics of Pt diffusion in n-type GaN film were investigated. The diffusion extent was characterized by secondary ion mass spectrometry. The temperature-dependent diffusion coefficients of Pt in n-GaN were 4.158 x 10−14, 1.572 x 10−13 and 3.216 x 10−13cm2/s at 650, 750 and 850C, respectively. The data could be described by:

D (cm2/s) = 6.627 x 10-9 exp[-0.914(eV)/kT]

These results indicated that the major diffusion mechanism of Pt in GaN was possibly an interstitial diffusion. In addition, it was also observed that the Pt atom may be a donor because the carrier concentration in Pt-diffused GaN was higher than that in un-diffused GaN. The optical property was studied by temperature-dependent photoluminescence measurement. The thermal quenching of the photoluminescence spectra for Pt-diffused GaN samples was also examined.

The Characteristics of Platinum Diffusion in n-Type GaN. D.H.Yeh, L.Z.Hsieh, L.B.Chang, M.J.Jeng: Applied Surface Science, 2007, 253[16], 6910-4