Impedance spectroscopic analysis of the InSe/ZnSe/InSe interface

摘要: In this paper, n-InSe/p-ZnSe/n-InSe (npn) thin-film transistors (TFTs) are deposited onto cubic (111)-oriented Ag, Au, and Al thin-film substrates. The properties of the structures are explored by means of X-ray diffraction and impedance spectroscopy in the frequency range of 10-1800 MHz. Although the Ag, Au, and Al substrates are observed to be well aligned with the cubic ZnSe, the electrical properties of these TFT for the np (InSe/ZnSe) and npn interfaces are different. Namely, while the capacitance of the TFT deposited onto the Ag substrate exhibited positive values, the capacitance of the TFT deposited onto Au and Al films is negative in the range of 10-1100 and 800-1800 MHz, respectively. In addition, even though the impedance of the Ag/np/Ag and Ag/npn/Ag heterojunction monotonically decreased with the increasing frequency, the impedance of Au/np/Au and Au/npn/Au interfaces exhibited resonance …