Impacts of Si-doping and resultant cation vacancy formation on the luminescence dynamics for the near-band-edge emission of Al0.6Ga0.4N films grown on AlN templates by metalorganic vapor phase epitaxy
Impacts of Si-doping and resultant cation vacancy formation on the luminescence dynamics for the near-band-edge emission of Al0.6Ga0.4N films grown on AlN templates by metalorganic vapor phase epitaxy
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DOI：
10.1063/1.4807906
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发表时间：
2013-06-07
影响因子：
3.2
通讯作者：
Uedono, A.
中科院分区：
文献类型：
--
作者：
Chichibu, S. F.;Miyake, H.;Uedono, A.
利用深紫外时间分辨光致发光和时间分辨阴极发光光谱研究了低压金属有机物气相外延生长的C面Si掺杂Al 0. 6Ga 0. 4N薄膜在250 nm附近的近带边（NBE）发光动力学.对于Si掺杂浓度[Si]低于1.9 × 10（17）cm（-3）的薄膜，掺杂通过表面活性剂效应或H3SiNH2形式的反应物掺杂的帮助降低了阳离子空位[V-III]的浓度。然而，当[Si]超过10（18）cm（-3）时，室温无辐射寿命，以及相应的弱激发态内量子效率的等效值急剧下降。同时，深态发射带与NBE发射的强度比突然增加。因为[Si]的增加基本上引起[V-III]的增加，（对于倒置的右垂直Si倒置的左垂直> 1.9 × 10（17）cm（-3）），并且对于[Si]= 4.0 × 10（18）cm（-3）的膜最终观察到Si的过补偿，建议形成诸如V-III-Si-III的含Si的受主型天然缺陷复合物。(C)2013 AIP Publishing LLC.
Luminescence dynamics for the near-band-edge (NBE) emission peak at around 250 nm of c-plane Si-doped Al0.6Ga0.4N films grown on AlN templates by low-pressure metalorganic vapor phase epitaxy were studied using deep ultraviolet time-resolved photoluminescence and time-resolved cathodoluminescence spectroscopies. For the films with the Si-doping concentration, [Si], lower than 1.9 x 10(17) cm(-3), the doping lessened the concentration of cation vacancies, [V-III], through the surfactant effect or the aid of the reactant doping in a form of H3SiNH2. However, the room-temperature nonradiative lifetime, and, consequently, the equivalent value of internal quantum efficiency in the weak excitation regime steeply decreased when [Si] exceeded 10(18) cm(-3). Simultaneously, the intensity ratio of the deep-state emission band to the NBE emission abruptly increased. Because the increase in [Si] essentially gives rise to the increase in [V-III] (for inverted right perpendicularSiinverted left perpendicular > 1.9 x 10(17) cm(-3)) and the overcompensation of Si is eventually observed for the film with [Si] = 4.0 x 10(18) cm(-3), the formation of acceptor-type native-defect complexes containing Si such as V-III-Si-III is suggested. (C) 2013 AIP Publishing LLC.