Publication Date:
2016-11-30
Description:
We present physical and electrical characterization of niobium-doped zinc oxide (NbZnO) for thin film transistor (TFT) applications. The NbZnO films were deposited using atomic layer deposition. X-ray diffraction measurements indicate that the crystallinity of the NbZnO films reduces with an increase in the Nb content and lower deposition temperature. It was confirmed using X-ray photoelectron spectroscopy that Nb 5+ is present within the NbZnO matrix. Furthermore, photoluminescence indicates that the band gap of the ZnO increases with a higher Nb content, which is explained by the Burstein-Moss effect. For TFT applications, a growth temperature of 175 °C for 3.8% NbZnO provided the best TFT characteristics with a saturation mobility of 7.9 cm 2 /Vs, the current On/Off ratio of 1 × 10 8 , and the subthreshold swing of 0.34 V/decade. The transport is seen to follow a multiple-trap and release mechanism at lower gate voltages and percolation thereafter.
Print ISSN:
0003-6951
Electronic ISSN:
1077-3118
Topics:
Physics
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