Hydrothermally Synthesized Bi-Doped CdTe Nanoparticles with Tunable Optical and Photoresponse Properties for Visible Photodetectors

The remarkable applicability and unique properties of CdTe nanoparticles make them vital in various applications such as optoelectronics and photovoltaics. It has been demonstrated that adding a metal dopant to a nanomaterial matrix significantly improves its characteristics, increasing its potential for a variety of applications. In this work, a simple hydrothermal synthesis process for bidoped CdTe nanoparticles is reported, wherein four distinct samples are generated by adjusting the concentration of Bi doping. Structural analysis using X-ray diffraction (XRD) confirmed the presence of the CdTe cubic phase in the material with observable phase shifts due to Bi incorporation. Rietveld refinement of the XRD results further enabled a detailed structural analysis. Raman spectroscopy provided insights into the different vibrational modes of CdTe, while transmission electron microscopy analysis further elucidated the CdTe phase and determined interplanar spacing values. Morphological examination via field emission scanning electron microscopy revealed a consistent nanoparticle-like morphology, unaffected even by increased Bi concentration. Elemental analysis conducted through inductively coupled plasma mass spectrometry offered valuable insights into the composition of the material. Furthermore, UV-vis analysis revealed a decrease in the bandgap, indicating potential shifts in the material's optical properties. Notably, the photoresponse study demonstrated an increase in current value, as well as alterations in the rise and decay times of the material. These properties highlight its potential for various optical and electrical applications. Overall, these findings underscore the promising prospects of bidoped CdTe nanoparticles in various advancements.