Deep-level-transient spectroscopy of heavily Al-doped ZnSe layers grown by molecular-beam epitaxy

D. C. Oh, T. Takai, T. Hanada, M. W. Cho, T. Yao, J. S. Song, J. H. Chang, F. Lu

研究成果: Article査読

6 被引用数 (Scopus)


Using deep-level-transient spectroscopy, we have investigated deep levels in heavily Al-doped ZnSe layers grown by molecular-beam epitaxy. The Al concentration of the ZnSe layers lies in the range of 5 × 10 18-9 × 1018 cm-3. The ZnSe:Al layers exhibit two electron-trap centers with the thermal activation energies of 0.16 eV (ND1) and 0.80 eV (ND2). ND2 is a dominant trap center with a trap density of 3 × 1016 cm-3, while the trap density of ND1 is estimated to be 2 × 1015 cm-3. However, ND2 shows anomalous behaviors, different from isolated point defects, in the following points: (1) the emission peak of ND2 moves to the low temperature side with increasing filling pulse duration; (2) the emission peak of ND2 is broader than theoretically calculated one for an isolated point defect; and (3) the capacitance-transient curve is nonexponential. It is observed by high-resolution x-ray diffraction that heavy Al doping results in the relaxation and plastic deformation of the ZnSe lattice. These behaviors can be ascribed to extended defects with a broad energy spectrum. By assuming a Gaussian distribution of deep levels due to extended defect, the broad emission peak is successfully simulated.

ジャーナルJournal of Applied Physics
出版ステータスPublished - 2004 12月 15

ASJC Scopus subject areas

  • 物理学および天文学(全般)


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