Akademik Veri Yönetim Sistemi
Journal of Materials Science: Materials in Electronics, cilt.28, sa.23, ss.17948-17960, 2017 (SCI-Expanded)
Polyvinyl alcohol capped Bi2S3 semiconductor nanocrystals were prepared by microwave-assisted and ultrasound-assisted methods after heat treatment in open air at 300 °C for 1 h. The optical, structural and morphological properties of them have been characterized by XRD, UV–Visible, FT-IR, SEM, TEM techniques. The XRD pattern shows the formation of nano-crystalline Bi2S3 and the UV–Vis spectroscopy results show a blue shift of about 1.5 and 1.6 eV for microwave and ultrasound-assisted methods, respectively. These values are due to the confinement of very small nanostructures. In order to determine electrical characteristics, the SBDs measurements of current, capacitance and conductance versus voltage (I–V, C–V, and G/ω−V) were performed at room temperature. Fermi energy level (EF), donor doping atoms (ND), and barrier height (ΦB) values were obtained by C−2–V plots at reverse biases. The voltage dependent profile of series resistance (Rs) was extracted by the Nicollian-Brews method. The energy dependent profiles of Nss were also obtained from the forward bias I–V data by considering voltage dependent ideality factor (n) and effective barrier height (Φe) for two type diodes. The values of the rectifying ratio (RR) and BH for the ultrasound -assisted interlayer are found greater than the microwave-assisted interlayer. The double-logarithmic I–V plots show three distinct linear regimes which are corresponding to low, intermediate and high forward biases for two structures and in these regions, the dominant current-transport was found via trap-charge limited current and space-charge-limited-current mechanisms, respectively. The value of BH obtained from the forward bias I–V is lower than at about EF from the reverse bias C–V measurement because of the nature of measurement techniques. These observations of low leakage current and higher RR, Rsh and BH for ultrasound-assisted interlayer MPS structure was confirmed that it has good performance when compared to the microwave-assisted interlayer MPS structure.