Preparation of Bi2Sr2CaCu2Ox Thin Film by Pulsed Laser Deposition for Optoelectronic Devices Application

Abstract

We report on the fabrication of Bi2Sr2CaCu2Ox (BSCCO) nanostructure films by pulsed laser deposition technique (PLD). The structural and optical properties of nanostructured Bi2Sr2CaCu2Ox film were investigated. X-ray diffraction (XRD) studies of the films prepared at 6.5 and 8 J/cm2 showed that the films are crystalline in nature with orthorhombic phase. Scanning electron microscopy (SEM) investigation confirmed that the deposited film has spherical grains and the mean grain size of the film was found to be increased from 150 nm to 250 nm as laser energy density increased from 6.5 to 8 J/cm2. The value of the optical energy gap of the film decreased from 2.24 to 1.7 eV when the energy density increased. The optoelectronic properties of the Bi2Sr2CaCu2Ox/Si heterojunction photodetector have been investigated. The photodetectors exhibited rectification properties and the ideality factor of the photodetectors deposited at 6.5 and 8 J/cm2 were 2.3 and 4.2, respectively. The on/off ratio of the photodetectors was found to be 761 and 385 for the photodetectors prepared at 6.5 and 8 J/cm2, respectively. A responsivity of 514 mA/W at 860 nm was obtained for photodetector prepared with 6.5 J/cm2.