Disorder induced conductivity enhancement in SHI irradiated undoped and N-doped 6H-SiC single crystals

作者：Sivaji K^*; Viswanathan E; Sellaiyan S; Murugaraj R; Kanjilal D

来源：Journal of Materials Science: Materials in Electronics , 2016, 27(11): 11825-11833.

DOI：10.1007/s10854-016-5323-6

We have studied undoped and N-doped 6H-SiC in its pristine and swift heavy ion (SHI) irradiated (150 MeV Ag12+ ions) forms by impedance spectroscopy at low temperatures. Fitting analysis of the complex impedance spectra reveals two time constants (R (1) Q (1) and R (2) Q (2)) for the irradiated samples and single time constant (R (1) Q (1)) for the pristine undoped and N-doped samples. This indicates a decrease in the grain interior conductivity (sigma(dc)) for the irradiated undoped 6H-SiC and an increase for the N-doped samples. The increased conductivity in the irradiated N-doped samples is due to the possibility of defect trapping and by the defect. The Activation energy (E (a)) exhibited an increase in the undoped samples and decrease in the N-doped samples. The sigma (dc) and the E (a) results suggest that the (de-)trapping effect on the defect states is significant in the irradiated samples. Furthermore, the impedance results support the formation of homogenous/heterogeneous defect structures in the irradiated samples. Impedance studies also reveals the disappearance of the charge carriers due to the (de-) trapping at the defect states at damage zone interface (DZI). The presence of disorder and the nature of the disorder are discussed.

• 出版日期2016-11
• 单位MIT