The Analysis of Inhomogeneous Barrier Height in In/SnTe/Si/Ag Diode

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Gullu H. H., YILDIZ D. E.

JOURNAL OF POLYTECHNIC-POLITEKNIK DERGISI, vol.21, no.4, pp.919-925, 2018 (ESCI) identifier


SnTe thin film layer was fabricated by magnetron sputtering technique on n-Si substrate, and the electrical properties of the In/SnTe/Si/Ag diode structure was investigated by using temperature dependent forward bias current-voltage (I-V) measurements. The main diode parameters were calculated according to the thermionic emission (TE) model and they were found in an abnormal behavior with change in temperate in which zero-bias barrier height (Phi(B0)) increases and ideality factor (n) decreases with increasing temperature. Therefore, the total current flow though the junction was expressed by the Gaussian distribution (GD) of barrier height. The plot of Phi(B0) vs q/2kT showed the existence of inhomogeneous barrier formation and evidence for the application of Gaussian function to identify the distribution of low barrier height patches. The mean barrier height was found as 1.274 with the 0.166 eV standard deviation. From the modified Richardson plot, Richardson constant was calculated as 119.5A/cm(2)K(2) in very close agreement with the reported values. Additionally, the effects of the series resistance (R-s) were analyzed by using Cheung's function. Distribution of the interface states (D-it) were extracted from the I-V characteristics and found in increasing behavior with decreasing temperature.