Photoluminescence quenching of a CdS nanoparticles/ZnO nanorods core–shell heterogeneous film and its improved photovoltaic performance

• Published in: Optical materials 2014-11, Vol.37, p.766-772
• Main Authors: Vanalakar, S.A., Mali, S.S., Suryawanshi, M.P., Tarwal, N.L., Jadhav, P.R., Agawane, G.L., Gurav, K.V., Kamble, A.S., Shin, S.W., Moholkar, A.V., Kim, J.Y., Kim, J.H., Patil, P.S.
• Format: Article
• Language: English
• Subjects: CdS nanoparticle; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Core–shell heterogeneous film; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Materials science; Nanocrystalline materials; Nanocrystals and nanoparticles; Nanoscale materials and structures: fabrication and characterization; Optical materials; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Optics; Other nonlinear optical materials; photorefractive and semiconductor materials; Photoluminescence; Photovoltaic characterization; Physics; ZnO nanorods
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2014.09.005

[Display omitted] •PL quenching of CdS/ZnO core–shell nanoparticles was observed in the presence of CdS nanocrystals.•Injection of electrons from CdS conduction band into the ZnO conduction band upon excitation was confirmed by PL quenching.•CdS nanoparticles deposited over ZnO nanorod at relatively low temperature. CdS nanoparticles/ZnO nanorods core–shell heterogeneous thin films were successfully fabricated using a chemical bath deposition process. X-ray diffraction (XRD), optical spectroscopy and field emission scanning electron microscopy (FE-SEM) were used for the characterization of the samples. Photoluminescence (PL) properties of the CdS nanoparticles/ZnO nanorods core-shell heterogeneous films were studied using PL spectroscopy. The injection of electrons from the CdS conduction band into the ZnO conduction band upon excitation was confirmed by PL quenching. The PL quenching in the present study demonstrated that more than one CdS nanoparticle is capable of networking with the single ZnO nanorod and taking an active part in the charge injection process. By attaching the CdS nanoparticles, the authors found the surface photovoltaic characteristics of ZnO were changed significantly. With a liquid electrolyte as the hole transport medium, CdS nanoparticles/ZnO nanorods core–shell heterogeneous film exhibited a short-circuit current density of 3.62mAcm−2 and an open-circuit voltage of 643mV with a total light-to-electricity power conversion efficiency of 1.48% under visible light.