Electrical and optical studies of pure and Ni-doped CdS quantum dots

Abstract

Quantum dots of CdS and Ni-doped CdS were synthesized through chemical precipitation method using a high-boiling solvent. Nanocrystallinity of the as prepared nanostructure is confirmed using X-ray diffraction (XRD). The mean crystal size obtained by full-width half maxima (FWHM) analysis is 3.33 nm for CdS, 3.37 nm for CdS:Ni (2 mM) and 3.39 nm for CdS:Ni (4 mM). The electrical conductivity data reveal semiconducting behaviour of both pure CdS and Ni-doped CdS nano-crystals. The optical absorption analysis conducted in UV-vis range 200-900 nm reveals the transparency of these nanocrystals in entire visible range but not in ultraviolet range. The results based on optical analysis yield band gap values as 2.65 eV for CdS, 2.59 eV for CdS:Ni (2 mM) and 2.53 eV for CdS:Ni (4 mM) nanoparticles. This implies that pure CdS and Ni doped CdS are blue shifted with respect to the bulk CdS (2.42 eV); however, Nickel doped CdS nanocrystals are red shifted with respect to pure CdS nanocrystals.

Ferromagnetic behavior of Cd1−xNixS nanorods: a novel study

“…The doped CdS registers blue shift-confirmed by XRD showing decrease in crystallite size, which, in turn, induces change in the electronic band structure of the host and thereby is responsible for higher energy band [21]. In addition to quantum confinement, smaller atomic radius of Ni atom is also responsible for increase in bandgap [15].…”

“…Firdous et al [15] synthesized the Ni-doped CdS quantum dots through chemical precipitation method using a high-boiling solvent. They also studied the effect of Nidoping on the electrical and the optical properties.…”

Enhanced photoconductivity in CdS/betanin composite nanostructures

“…44 In most of the cases, impurity addition in CdS reduces the band gap with increase in concentration. [45][46][47] The absorption spectra of composite system have an additional band edge (bare CdS has only one absorption edge at 511 nm corresponding to the energy 2.42 eV) in the lower wavelength region. The energy corresponding to the intermediate band (since its value lies below the band gap of the synthesized CdS nanoparticle) is shied towards the red region with betanin percentage.…”

Visible‐Light Driven Ni‐Incorporated CdS Photocatalytic Activities for Azo‐Bond Cleavages with Hydrogenation Reaction

“…to enhance the efficiency reaction [18–19] . It is noticed that the incorporation of Ni into CdS enhances the properties for photovoltaic parameters, [20] high voltage applications, [21] and optical applications [22] . However, the application for photocatalytic hydrogenation for the chemical conversion is not yet done.…”