Interpretation of barrier height inhomogeneities in Au/In2S3/SnO2/(In-Ga) structures at low temperatures

TECİMER H., Altindal S., Aksu S., Atasoy Y., BACAKSIZ E.

JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS, vol.28, no.10, pp.7501-7508, 2017 (SCI-Expanded) identifier identifier


The structure of Au/In2S3/SnO2/(In-Ga) have been examined by current-voltage (I-V) data between 125 and 300 K temperature levels at forward biases. The zero-bias barrier height (I broken vertical bar (Bo) ) and the ideality factor (n) obtained from the linear part of lnI-V characteristics were achieved as cogently dependent to temperature. The I broken vertical bar (Bo) values increase with the increment at temperature where as those of n decrease. The obtained positive temperature coefficient (alpha = 2.1 x 10(3) eV/K) of I broken vertical bar (Bo) was not compatible with the In2S3 band gap's negative temperature coefficient or the ideal diode's barrier height (BH) behavior. Hence, the plot of I broken vertical bar (Bo) vs. q/2kT have figured to attain an evidence of a Gaussian distribution (GD) of the barrier heights (BHs). The figure for I broken vertical bar (Bo) vs. q/2kT was used to obtain standard deviation (sigma (o) ) and mean values of BH as 0.88 eV and 0.116 V, respectively. In this way, we modified Richardson [ln(I (o) /T (2)) - q (2)sigma(o) (2)/2k (2) T (2)] vs. q/kT plot, and the values of and effective Richardson constant (A*) were extracted as 0.87 eV and 10.25 A/cm(2) K-2 from this plot, respectively. It was educed that the I-V data which depends on temperature subjected to the thermionic emission (TE) theory can be set out in full with single GD of the BHs.