Characterization of CdS/Sb2Te3 micro/nano-interfaces

In this study, transparent micro/nano heterojunction structures are designed and characterized. The X-ray diffraction, optical and impedance spectroscopy techniques are employed for this purpose. In the design, a CdS film of thickness of 0.5 mu m was used as the micro layer. The nano-layer is composed of 20 or 50 nm thick Sb2Te3 film. The analysis of the experimental data has shown that the CdS films exhibit a Major hexagonal and minor orthorhombic phases. While the grain size of the microlayer decreases, the strain, defect density and stacking faults increases when the nano-layer is co-evaporated. In addition, the absorption of the CdS is improved by similar to 4 times and by similar to 8 times in the visible and infrared ranges of light. The dielectric constant of CdS is also increased by this method.The calculated changes in the energy band gap and energy band offsets are found to be sufficient to allow using the micro/nano heterojunction device in optoelectronic and microwave technologies. The recombination mechanisms of the device that were discovered through the analysis of the photocurrent was observed to be mostly dominated by the trap-assisted recombination at high light powers. On the other hand, while the Yb/CdS/Sb2Te3 anisotype device performed well as a low pass microwave filter, the hybrid Au/CdS/Sb2Te3 device behaved as high pass filter in the frequency domain of 10-1800 MHz. (C) 2018 Elsevier GmbH. All rights reserved.