Intrinsic luminescence and core structure of freshly introduced a-screw dislocations in n-GaN
Intrinsic luminescence and core structure of freshly introduced a-screw dislocations in n-GaN
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DOI：
10.1063/1.5011368
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发表时间：
2018-04
影响因子：
3.2
通讯作者：
O. Medvedev;O. Vyvenko;E. Ubyivovk;S. Shapenkov;A. Bondarenko;P. Saring;M. Seibt
中科院分区：
文献类型：
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作者：
O. Medvedev;O. Vyvenko;E. Ubyivovk;S. Shapenkov;A. Bondarenko;P. Saring;M. Seibt
利用阴极发光和透射电子显微镜（TEM）研究了低欧姆非故意掺n型GaN晶体基面和棱柱面的划痕或压痕引起的位错。在70 ~ 420 K的温度范围内，A螺位错的直段有较强的发光。位错相关发光（DRL）的光谱由窄谱线组成，谱线相对于带隙红移约0.3 eV。透射电镜显示了螺旋位错的解离特征，并在其相交处形成了扩展节点。通过对DRL的温度、功率和应变关系的分析，认为DRL是由解离螺旋位错的部分和层错（SF）带形成的一维量子阱束缚的直接和间接激子引起的。
Dislocations introduced by the scratching or by the indentation of the basal and prismatic surfaces of low-ohmic unintentionally n-type doped GaN crystals were investigated by means of cathodoluminescence and transmission electron microscopy (TEM). A strong luminescence of straight segments of a-screw dislocations was observed in the temperature range of 70–420 K. The spectrum of dislocation related luminescence (DRL) consisted of a doublet of narrow lines red shifted by about 0.3 eV with respect to the band gap. TEM revealed dissociated character of the screw dislocations and the formation of extended nodes at their intersection. From the analysis of the DRL spectral doublet temperature, power and strain dependences DRL was ascribed to direct and indirect excitons bound by 1D quantum wells formed by partials and stacking fault (SF) ribbon of dissociated screw dislocation.