Coupling of codoped In and N impurities in ZnS:Ag: Experiment and theory

Kochi University of Technology, Kamikawa, Hokkaidō, Japan
Journal of Applied Physics (Impact Factor: 2.18). 01/2002; 91(2):760-763. DOI: 10.1063/1.1421628
Source: OAI


A vapor-phase-grown epitaxial ZnS:Ag layer simultaneously codoped with In and N on GaAs substrate exhibited a 436-nm light emission and p-type conduction with a low resistivity. X-ray photoemission spectroscopy revealed that the In 3d5/2 electron binding energy of the codoped ZnS:In,N layer was smaller by 0.5 eV than that of the ZnS:In independently doped layer, although the 2p3/2 electron binding energies of Zn and S of the codoped layer agreed well with those of the independently doped layer, respectively. The reduction of binding energy was ascribed to an increase in the electronic relaxation energy for core-hole states in photoemission and reflects a large charge transfer between the In and N atoms at the first neighbor sites through covalent sp3 bonding orbitals. An increase of the spectral intensity at around 4 eV relative to the valence band maximum observed for the codoped layer corresponds to a new state at −3.67 eV from the valence band maximum due to a strong coupling between the In 5s and N 2p orbitals at the first neighbor sites, derived from a first-principle band structure calculation for ZnS:(In,2N). © 2002 American Institute of Physics.

Download full-text


Available from: Shigemi Kohiki,
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We discuss the condition for delocalization of holes in N-doped ZnO, ZnS, and ZnTe. For N-doped ZnO and ZnS, we find large energy reduction due to ionic polarization and a narrow N-impurity band at the top of the valence band compared with those for N-doped ZnTe. These are due to the significant difference between the static and optical dielectric constants of ZnO and ZnS, which have a fair degree of ionic character. We propose a design doping method which involves codoping donors with N acceptors to satisfy the condition for delocalization.
    Japanese Journal of Applied Physics 05/2003; 42(Part 2, No. 5B). DOI:10.1143/JJAP.42.L514 · 1.13 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Photoluminescence (PL) properties of differently doped nanocrystalline ZnS encapsulated by ZnO (ZnS/ZnO) are reported. It is found that in all cases aluminium as an extra/additional dopant leads to PL enhancement. In comparison to reported blue emitting bulk ZnS:Ag, or green emitting bulk ZnS:Cu, our nanocrystalline samples show a different PL emission profile. This observation is attributed to nanogranule formation, different dopant levels and ZnO capping related energy level modifications. (c) 2007 Elsevier Ltd. All rights reserved.
    Solid State Communications 05/2007; 142(5):261-264. DOI:10.1016/j.ssc.2007.02.023 · 1.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Zinc sulfide (ZnS) is one of the first semiconductors discovered. It has traditionally shown remarkable versatility and promise for novel fundamental properties and diverse applications. The nanoscale morphologies of ZnS have been proven to be one of the richest among all inorganic semiconductors. In this article, we provide a comprehensive review of the state-of-the-art research activities related to ZnS nanostructures. We begin with a historical background of ZnS, description of its structure, chemical and electronic properties, and its unique advantages in specific potential applications. This is followed by in-detail discussions on the recent progress in the synthesis, analysis of novel properties and potential applications, with the focus on the critical experiments determining the electrical, chemical and physical parameters of the nanostructures, and the interplay between synthetic conditions and nanoscale morphologies. Finally, we highlight the recent achievements regarding the improvement of ZnS novel properties and finding prospective applications, such as field emitters, field effect transistors (FETs), p-type conductors, catalyzators, UV-light sensors, chemical sensors (including gas sensors), biosensors, and nanogenerators. Overall this review presents a systematic investigation of the ‘synthesis-property-application’ triangle for the diverse ZnS nanostructures.
    Progress in Materials Science 02/2011; 56(2):175-287. DOI:10.1016/j.pmatsci.2010.10.001 · 27.42 Impact Factor
Show more