Blue light-emitting diode based on ZnO
Blue light-emitting diode based on ZnO
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DOI：
10.1143/jjap.44.l643
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发表时间：
2005-01-01
期刊：
影响因子：
--
通讯作者：
Kawasaki, M
中科院分区：
文献类型：
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作者：
Tsukazaki, A;Kubota, M;Kawasaki, M
通过沉积在p型ZnO顶层上的半透明电极，从ZnO p-i-n同质结二极管中观察到中心在440 nm附近的近带边蓝色电致发光（EL）带。EL峰值能量与等效p型ZnO层的光致发光峰值能量一致，表明从n型层到p型层的电子注入主导电流，从而引起p型层中的辐射复合。电荷注入的不平衡被认为是源于p型层中较低的多数载流子浓度，其比n型层中的多数载流子浓度低一个或两个数量级。的电流-电压特性示出了几百欧姆的串联电阻的存在下，对应于底部的n型ZnO内的电流扩散电阻。导电ZnO衬底的使用可以解决后一个问题。
A near-band-edge bluish electroluminescence (EL) band centered at around 440 nm was observed from ZnO p-i-n homojunction diodes through a semi-transparent electrode deposited on the p-type ZnO top layer. The EL peak energy coincided with the photoluminescence peak energy of an equivalent p-type ZnO layer, indicating that the electron injection from the n-type layer to the p-type layer dominates the current, giving rise to the radiative recombination in the p-type layer. The imbalance in charge injection is considered to originate from the lower majority carrier concentration in the p-type layer, which is one or two orders of magnitude lower than that in the n-type one. The current-voltage characteristics showed the presence of series resistance of several hundreds ohms, corresponding to the current spread resistance within the bottom n-type ZnO. The employment of conducting ZnO substrates may solve the latter problem.