Cimilli Çatır, Fulya Esra

Ti/GO/n-InP Schottky barrier diode (SBD) is obtained by growing graphene oxide (GO) film on n/InP semiconductor using easy and economical spray pyrolysis method. The effect of GO as the interfacial layer on device performance of Ti/GO/n-InP SBD is investigated in detail. The optical absorbance spectra show that bandgap energy of the GO film is 3.57 eV. The optical transmittance value of 79.5% is in consistent with the absorbance spectra of GO film. The barrier heights (BHs) that are estimated for the Ti/GO/n-InP SBD vary from 0.263 to 0.980 eV (I–V) and 1.328 to 1.006 eV (C–V) from the I–V and C–V measurements in the temperature range of 100–400 K. The contradiction between the BHs from the I–V and C–V characteristics is discussed. The mean BH values are found to be Φb01 = 0.98 eV (250–400 K) and Φb02 = 0.73 eV (100–250 K) from the Φb0–1/2kT plot. From the modified Richardson plots based on a Gaussian distribution of BH, Φb01 = 0.93 (250–400 K) and Φb02 = 0.69 eV (100–250 K) and A* is calculated to be 12.44 and 12.73 A cm−2 K−2, respectively. The I–V–T and C–V–T measurements demonstrate that carrier transport mechanism of Ti/GO/n-InP is well explained by thermionic emission (TE) mechanism with a double Gaussian distribution of the Schottky barrier heights (SBHs).

Özakin, Oǧuzhan; Güzeldir, Betül; Yildirim, M. Ali; Saǧlam, Mustafa; Ateş, Aytunş

ZnS thin films were deposited on glass substrates using SILAR method at room temperature and ambient pressure. The relationship between refractive index and energy bandgap was investigated. The film thickness effect on the structural, morphological and optical properties of ZnS thin films was investigated. The crystalline and surface properties of the films improved with increasing film thickness. The energy bandgap values changed from 3.87 to 3.58 eV with increasing film thickness. The refractive index (n), high frequency dielectric constant (ε ∞) values were calculated by using the energy bandgap values as a function of the film thickness. Also, ZnS thin film was deposited directly on n-GaAs substrate for obtaining the Zn/ZnS/n-GaAs/In sandwich structure at room temperature. The sandwich structure demonstrated clearly rectifying behaviour by the current-voltage (I-V) curves at room temperature. From I-V characteristics n and φ b values were calculated as 1.894 and 0.632 eV at room temperature, respectively.