Chul Lee

Publications (3)4.71 Total impact

• Article: Defect-related luminescence of Mg-doped n-GaN grown by hydride vapour-phase epitaxy

  Chul Lee, Jae-Eun Kim, Hae Yong Park, S T Kim, H Lim
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  ABSTRACT: We study photoluminescence (PL) and photoluminescence excitation (PLE) spectra of Mg-doped n-GaN grown by hydride vapour-phase epitaxy. Defect-related red and blue emission bands around 1.85 eV and 2.90 eV, respectively, are observed in addition to the yellow emission band. The red and the blue emission bands are attributed to the recombinations involving the same Mg-related defects according to the result of the thermal annealing experiment. The PLE spectra of the red, the yellow, and the blue emission bands show that all of these emission bands can be interpreted in terms of a configuration coordinate (CC) diagram. The blue emission at 2.90 eV is attributed to the transition from the conduction band to the Mg-related deep acceptors. The CC diagram shows that the yellow luminescence is due to the transition from a deep donor state to a shallow acceptor state. A possible origin of the deep donor level is also discussed.
  Journal of Physics Condensed Matter 12/1998; 10(48):11103. · 2.55 Impact Factor
• Source

  Available from: ac.kr

  Article: Determination of conduction band tail and Fermi energy of heavily Si‐doped GaAs by room‐temperature photoluminescence

  Nam‐Young Lee, Kyu‐Jang Lee, Chul Lee, Jae‐Eun Kim, Hae Yong Park, Dong‐Hwa Kwak, Hee‐Chul Lee, H. Lim
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  ABSTRACT: A line‐shape analysis of room temperature photoluminescence (PL) spectra was carried out on Si‐doped GaAs samples grown by molecular beam epitaxy. The electron concentration n of the samples ranges from 1.0×10¹⁷ to 4.2×10¹⁸cm^-3. It was found that the conduction band tail η c and the Fermi energy ε f measured from the conduction band minimum can be expressed as η c =2.0×10^-8n^1/3(eV) and ε f =-0.074+1.03×10^-7n^1/3(eV), respectively. The PL peak energy, at which the electron concentration per unit energy in the conduction band is maximum, can also be expressed as 1.426+2.4×10^-14n^2/3(eV). © 1995 American Institute of Physics.
  Journal of Applied Physics 10/1995; · 2.17 Impact Factor
• Article: Clustering effect and residual stress in In_ {x} Ga_ {1-x} As/GaAs strained layer grown by metal-organic chemical-vapor deposition

  Insun Hwang, Chul Lee, Jae-Eun Kim, Hae Yong Park, E.-K. Suh, K. Y. Lim, H. J. Lee
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  ABSTRACT: We investigate the photoreflectance spectra of the thin and thick InxGa1-xAs/GaAs epitaxial heterostructures. It is observed that the In atoms are nonuniformly distributed at the interface of the substrate and the epilayer and a particular kind of phase whose In concentration is about 0.02 exists at the interface. Thus we believe that there is a stable InxGa1-xAs configuration at about x∼0.02, so that the In atoms cluster for x<0.02 but segregate for x>0.02. The epilayers are strained by the biaxial compressive stress due to lattice mismatch and also by the tensile stress introduced by the wavy shape of the epilayer. The tensile stress remains up to 5 μm thickness. The magnitude of the residual tensile strain is about 2/3 times that of the compressive strain due to the lattice mismatch.
  Phys. Rev. B. 03/1995; 51(12).