Temperature-dependent electrical properties of schottky barrier diodes based on carbon nanotube arrays

In this study, the current conduction mechanisms (CCMs) of the carbon nanotube Schottky barrier diodes (CNT SBDs) based on carbon nanotube arrays on an insulating quartz substrate are investigated using the forward current-voltage-temperature (I-V-T) measurements over a wide temperature range of 60 to 360 K. Anomalous temperature dependence of both the values of ideality factors (n) and Schottky barrier heights (SBHs) extracted from thermionic emission (TE) theory and Chueng's method were observed, as the SBHs increase whereas the ideality factors decrease with the increasing temperature from 60 to 360 K. The anomalous temperature dependence could be explained by the Gaussian distribution of the Schottky barrier heights. Furthermore, the contributions of generation-recombination, tunneling, and leakage current are all considered for the forward current of the CNT SBDs. The fitting results indicate that in the temperature range of 60 to 360 K, the main CCMs below 180 K are tunneling and leakage, while the main CCMs are dominated by TE and leakage above 300 K. In this work, the dependence of the electrical properties of CNT SBDs on temperature is reported in detail, which is helpful to better understand the electrical properties of CNT SBDs and improve their performance.