Structural and electrical properties of the Al/p-Cu^sub 2^ZnSnS^sub 4^ thin film schottky diode

In order to calculate the Schottky barrier parameters and to explain the resulting effects, the conduction mechanisms in a Schottky barrier should be known. In the present study, we investigated the structural and electrical properties of Al/p-Cu2ZnSnS4 (CZTS)/Mo thin film Schottky junction. Structural characterization was carried out using X-Ray diffraction and Raman Scattering whereas electrical characterization was performed by using the current-voltage (I-V) characteristics and by recording the AC impedance spectroscopy over a wide range of temperature up to 558 K in the frequency range 5 Hz-13 MHz. The complex impedance plots display one semicircle with equivalent circuit functions as typical parallel RC connected to a serial resistance. The characteristic parameters such as barrier height, ideality factor and series resistance have been calculated from the I-V measurements. At room temperature, this heterostructure has shown non-ideal Schottky behavior with an ideality factor of 1.56 and 0.829 µA as a saturation current. By the impedance spectroscopy technique, we have found that all of the serial resistance Rs and the parallel resistance Rp decrease by increasing temperature whereas the capacitance C0 increased from 0.76 to 1.07 µF. From the Arrhenius diagram, we estimated activation energy at 0.289 eV which represents the energy difference between the trap level and the valence band.