Synthesis of erbium doped cadmium oxide thin films and investigation of their optoelectronic properties: by sol–gel spin coating method
摘要
In this study, synthesis of erbium-doped and undoped cadmium oxide (CEr) thin films on glass substrates using the sol–gel spin coating method, a low-cost and scalable fabrication technique. The crystalline quality of the films with preferential orientation along the (111) plane is confirmed by structural analysis employing X-ray diffraction. A cauliflower-like surface structure with roughness varying from 112.10 to 156.81 nm is shown by morphological investigations utilizing atomic force and scanning electron microscopy. This surface structure is crucial for light interaction in optoelectronic applications. The presence of distinctive chemical bonds in the films is verified by Fourier transform infrared spectroscopy. Good crystallinity is indicated by Raman analysis, which reveals peaks at 293.5 and 402.6 cm-1 that correspond to longitudinal optical phonon modes. The potential of these films for blue light-emitting applications is shown by photoluminescence analysis, which shows a strong blue emission peak centred at 416 nm. Transmittance increases with Er doping, which is beneficial for transparent electrode applications. Based on optical studies, the optical band gap decreases with increasing dopant concentration, suggesting a change in the band structure. All things considered, these results show that Er-doped CdO thin films are viable options for next-generation optoelectronic applications, especially in transparent electronics and possible blue light-emitting devices.