Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2015
Student: KANİ MORAKİ
Supervisor: MEHMET MAHİR BÜLBÜL
Abstract:In this study, Au/C20H12/n-Si Schottky barrier diodes (SBDs) were fabricated and their main electrical parameters such as reverse-saturation current (Io), ideality factor (n), zero- bias barrier height (Bo), series and shunt resistances (Rs, Rsh) were determined by using the forward bias current-voltage-temperature (I-V-T) characteristics as 1.974x10-7A, 6.434, 0.351 eV, 30.22 and 18.96 k at 160 K and 1.061x10-6A, 2.34, 0.836 eV, 5.82 and 24.52 k at 380 K, respectively. Experimental results show that the value of n decrease with increasing temperature, but ΦBo increases. The change in ΦBo with temperature is not agreement with negative temperature coefficient of forbidden bad-gap of semiconductor (Si). Thus, ΦBo vs n, ΦBo and (n-1-1) vs q/2kT plots were drawn to obtain an evidence of a Gaussian distribution (GD) of the BHs and all of them have a straight line. The mean value of BH ( ̅Bo) was found as 0.983 eV from the intercept of ΦBo vs n plot (for n=1). Also, the value of ̅Bo and standard deviation (s) were found as 1.123 eV and 0.151 V from the slope and intercept of ΦBo vs q/2kT plot. By using the modified Richardson plot, the ̅Bo and Richardson constant (A*) values were obtained as 1.116 eV and 113.44 A.cm-2K-2 from the slope and intercept of this plot, respectively. It is clear that this value of A* (=113.44 A.cm-2K-2) is very close to their theoretical value of 112 A.cm-2K-2 for n-Si. In addition, the energy density distribution profile of surface states (Nss) was obtained from the forward bias I-V data by taking into account the bias dependent of the effective barrier height (e) and ideality factor n(V) for four different temperatures (120, 200, 300, and 400 K). In conclusion, the I-V-T measurements of the Au/C20H12/n-Si SBD in the whole temperature range can be successfully explained on the basis of thermionic emission (TE) theory with GD of the BHs.