Origin of ultraviolet electroluminescence in n‐ZnO/p‐GaN and n‐MgZnO/p‐GaN heterojunction light‐emitting diodes
Origin of ultraviolet electroluminescence in n‐ZnO/p‐GaN and n‐MgZnO/p‐GaN heterojunction light‐emitting diodes
复制标题
DOI：
10.1002/pssa.201330026
复制
发表时间：
2013-12
期刊：
影响因子：
--
通讯作者：
Chunyang Liu;Haiyang Xu;Jiangang Ma;Yichun Liu
中科院分区：
文献类型：
--
作者：
Chunyang Liu;Haiyang Xu;Jiangang Ma;Yichun Liu
在本工作中，我们设计并制备了一系列n-ZnO/p-GaN和n-MgZnO/p-GaN异质结。根据电致发光(EL)和光致发光(PL)光谱、电流-电压(I-V)特性和能带图，讨论了载流子输运和复合机制。对于氧化锌器件，在∼400 nm处的近紫外光发射归因于从氧化锌导带最小到GaN受主能级的空间-间接界面跃迁。而对于氧化镁二极管，它们的紫外电致发光与镁组分无关，被认为来源于GaN层中的施主-受主对(DAP)复合。我们的实验结果表明，在n-(Mg)ZnO/p-GaN异质结中很难实现纯的氧化锌或镁氧化锌的发射，针对(镁)氧化锌激子发射的合理的器件设计在进一步的工作中更为重要。
In this work, a series of n‐ZnO/p‐GaN and n‐MgZnO/p‐GaN heterojunctions are designed and fabricated. The carrier transport and recombination mechanism is discussed based on electroluminescence (EL) and photoluminescence (PL) spectra, current–voltage (I–V) characteristics as well as energy band diagram. For ZnO device, the near‐ultraviolet (UV) emission at ∼400 nm is attributed to the spatially‐indirect, interfacial transition from ZnO conduction band minimum to GaN acceptor level. While for MgZnO diodes, their UV EL is independent on Mg composition, is thought to origin from the donor–acceptor pair (DAP) recombination in GaN layer. Our experiment results suggest that pure ZnO or MgZnO emission can hardly be achieved in n‐(Mg)ZnO/p‐GaN heterojunctions, rational device design towards (Mg)ZnO exciton emission is more important in the further work.