Role of Bi3+ ions on structural, optical, photoluminescence and electrical performance of Cd0.9-xZn0.1BixS QDs
Aravind Krishnamoorthy, P. Sakthivel, I. Devadoss, V. M. Anitha Rajathi
Abstract
Abstract In this work, the Cd 0.9-x Zn 0.1 Bi x S QDs with different compositions of Bi 3+ ions (0 ≤ x ≤ 0.05) were synthesized using a facile chemical route. The prepared QDs were characterized for analyzing the structural, morphological, elemental, optical, band gap, photoluminescence and electrochemical properties. XRD results confirmed that the Cd 0.9-x Zn 0.1 Bi x S QDs have a cubic structure. The mean crystallite size was increased from ~ 2 to ~ 5 nm for the increase of Bi 3+ ions concentration. The optical transmittance behavior was decreased with increasing Bi 3+ ions. The scanning electron microscope images showed that the prepared QDs possessed agglomerated morphology and the EDAX confirmed the presence of doped elements as per stoichiometry ratio. The optical band gap was slightly blue-shifted for initial substitution (Bi 3+ = 1%) of Bi 3+ ions and red-shifted for further increase of Bi 3+ compositions. The optical band gap was ranged between 3.76 and 4.0 eV. High intense red emission was received for Bi 3+ (1%) doped Zn:CdS QDs. The red emission peaks were shifted to a higher wavelength side due to the addition of Bi 3+ ions. The PL emission on UV-region was raised for Bi 3+ (1%) and it was diminished. Further, a violet (422 nm) and blue (460 nm) emission were received for Bi 3+ ions doping. The cyclic voltammetry analysis showed that Bi 3+ (0%) possessed better electrical properties than other compositions of Bi 3+ ions.