Fabrication And Characterizatıon Of Au/Carmine/N-Gaas Schottky Diode By Spin Coating Technique

Abstract

Carmine thin films were obtained on both quartz glass and n-GaAs semiconductor using spin coating. Scanning electron microscopy (SEM) shows that the thin film has a uniform surface and the average grain size is 30.717 nm. Surface roughness was determined from atomic force microscopy (AFM). To determine transmission (T), reflection (R) and absorption (alpha) behavior, allowed direct band gap value (Eg), refractive index (n), extinction coefficient (k), dielectric coefficients (epsilon(1)- epsilon(2)) of the thin film, optic spectrometry was employed. The allowed direct band gap value of the carmine thin film is found as 3.94 eV. The current-voltage (I-V) curves of the Au/Carmine/n-GaAs Schottky barrier diodes (SBDs) were measured at room temperature. The characteristic parameters of the Au/nGaAs and Au/Carmine/n-GaAs diodes such as effective barrier height (Phi(b0)), ideality factor (n), and series resistance (R-S) were obtained from the I-V measurements. I-V characteristic parameters of the devices were analyzed via using with the standard thermionic emission (TE) theory at very low forward bias voltage regime. The ideality factory and effective barrier height values were found in the range of 1.359-2.090 and 0.858-1.001 eV for modified SBDs, respectively. Furthermore, Cheung functions were also used to evaluate the characteristic parameters of the SBDs. The obtained diode parameters from I-V with Cheung functions were compared