Study of barrier height and trap centers of Au/n-Hg3In2Te6 Schottky contacts by current-voltage (I-V) characteristics and deep level transient spectroscopy

Abstract

The temperature-dependent electrical characteristics of the Au/n-Hg3In2Te6 Schottky contact have been studied at the temperature range of 140 K–315 K. Based on the thermionic emission theory, the ideality factor and Schottky barrier height were calculated to decrease and increase from 3.18 to 1.88 and 0.39 eV to 0.5 eV, respectively, when the temperature rose from 140 K to 315 K. This behavior was interpreted by the lateral inhomogeneities of Schottky barrier height at the interface of Au/n-Hg3In2Te6 contact, which was shown by the plot of zero-bias barrier heights Фbo versus q/2kT. Meanwhile, it was found that the Schottky barrier height with a Gaussian distribution was 0.67 eV and the standard deviation σ0 was about 0.092 eV, indicating that the uneven distribution of barrier height at the interface region. In addition, the mean value of Φ¯b0 and modified Richardson constant was determined to be 0.723 eV and 62.8 A/cm2K2 from the slope and intercept of the ln(Io/T2) – (qσ02/2k2T2) versus q/kT plot, respectively. Finally, two electron trap centers were observed at the interface of Au/n-Hg3In2Te6 Schottky contact by means of deep level transient spectroscopy.