ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Characterization of ZnO@CdSe heterostructures with quantum-confined CdSe for optoelectronic applications

S. Ildan Ozmen

Advanced Technology Education Research and Application Center, Mersin University, Mersin, Turkey

E-mail: sevdaildan@mersin.edu.tr

Received: 31 December 2025  Accepted: 20 February 2026

Abstract:

In this study, ZnO@CdSe heterostructure was fabricated by synthesizing ZnO nanowires (NWs) via electrochemical anodization of a zinc foil and subsequently depositing a CdSe nanoparticles using the chemical bath deposition (CBD) method. The structural, morphological, optical, and charge transfer resistance properties of ZnO NWs and ZnO@CdSe heterostructures were comparatively analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform-infrared spectroscopy (FT-IR), UV–visible, and electrochemical impedance spectroscopy (EIS). SEM and TEM analysis demonstrated that CdSe nanoparticles were deposited on the surface of ZnO NWs, verifying the fabrication of ZnO@CdSe heterostructures. The Rietveld refinement of the XRD data confirmed the successful formation of ZnO nanowires and ZnO@CdSe heterostructures, while the average crystallite size of CdSe was determined to be 2.51 nm, indicating quantum confinement effects. Also, quantitative analysis results demonstrated that ZnO@CdSe heterostructures composed 16% Zn and 54% ZnO and 30% CdSe phase constitutes of the heterostructure. Optical measurements showed that the band gap of ZnO NWs (3.09 eV) increased to 3.31 eV after CdSe deposition. EIS revealed an improvement in interfacial charge transfer upon CdSe deposition, as by a reduction in solution resistance (Rs) from 7.90 to 5.65 Ω and a decrease in charge-transfer resistance (R₁) from 34.05 to 31.29 Ω. These results demonstrate that nanocrystalline CdSe with crystallite sizes well within the quantum confinement regime significantly improves the charge transfer behavior of ZnO NWs, suggesting that the ZnO@CdSe heterostructure is a promising material for next-generation optoelectronic and solar energy conversion devices.

Keywords: ZnO; CdSe; Quantum dots; Optoelectronics; Rietveld refinement

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-04759-9

Chemical Papers 80 (4) 4457–4470 (2026)