Ga-N共掺n-ZnO/p-ZnO(Sb)纳米阵列蓝光LED发光性能研究

ZnO, as a wide bandgap semiconductor that with large exciton binding energy and high ultraviolet-blue light emission efficiency，is of considerable interest for applied in next-generation solid-state lighting and multicolor electroluminescence display. However, the dopped related high defect recombination was resulted the broad and low efficiency emission, which was one of the main challenges for one-dimensional ZnO nanowire arrays based blue LED..In this project, we propose to obtain the Ga-N codoped ZnO nanowire arrays by chemical vapor deposition method as the first step. Then, the Sb doped p type ZnO nanowire will epitaxy grown on the Ga-N:ZnO nanowire by the two-step growth method. Finally, the n type Ga-N:ZnO/p-ZnO(Sb) homojunction nanowire arrays LED device will be fabricated. In detailed, we will modulated the charge density and bandgap narrow shifting of ZnO nanowire by concrolling Ga-N dopped ratio and concentration. We will also fabricated the single ZnO p-n homojunction nanowire devices, to study the electroluminescence properties of doped p-n homojunction nanowire. The mechanism of electron-hole recombination in Ga-N:ZnO/p-ZnO(Sb) nanowire arrays, the emission efficiency and the relationship between bandgap structure of ZnO p-n homojunction will be revealed in this project. This work will provide the theory and experiment basis for developing novel ZnO blue LED, involved the pivotal materials synthesis, charge carrier transport and electroluminescence properties, which has potential application in next-generation low-cost and high efficiency light source.

ZnO具有较高的激子束缚能和蓝紫光出射效率，有望成为下一代固态照明和全色显示的核心光源。然而，掺杂引入的高浓度缺陷态复合导致光谱宽化和发光效率降低等因素制约着一维ZnO纳米阵列单色蓝光LED器件的发展。本项目采用化学气相沉积法制备Ga-N共掺杂ZnO纳米阵列，利用原位外延生长技术实现n型Ga-N:ZnO/p-ZnO(Sb)同质结纳米阵列，构筑ZnO基高质量蓝光LED器件。研究Ga-N共掺后n型ZnO的载流子浓度和禁带宽度的变化规律；探索单根纳米线同质p-n结的光发射特性，建立相适应的能带结构模型，揭示Ga-N:ZnO/p-ZnO(Sb)纳米阵列的电子-空穴复合发光机理，实现发光波长与单色性的调控。本项目的顺利实施对ZnO基蓝光LED器件关键材料制备技术、电学输运和电致发光机理奠定重要的理论和实验基础。

氧化锌因较高的激子束缚能和蓝紫光发射效率，是新型照明和显示技术领域的关注焦点。针对氧化锌的掺杂缺陷和p型掺杂困难的问题，本项目采用化学气相沉积法制备了镓氮共掺氧化锌纳米线阵列，采用外延生长技术实现了锑掺杂氧化锌纳米线阵列的可控合成，并构建了氧化锌同质外延蓝光LED器件。研究发现（1）通过调控掺杂源的配料摩尔比，实现氧化锌纳米线中镓氮掺杂含量的调控，镓氮最高掺杂比例可分别达到14.62%和27.67%。（2）以氧化锌单晶为基底，采用化学气相沉积外延生长了锑掺杂氧化锌纳米线阵列。外延生长的锑掺杂氧化锌纳米线为（002）方向的单晶氧化锌，摇摆曲线半高宽为0.47 mrad，显示出较高的结晶质量。通过霍尔效应和单根纳米线FET器件两种测试方法证实，在合适的掺杂浓度（3%-4.5%）下，锑掺杂氧化锌纳米线表现出p型导电特性，空穴浓度在2.0×1014cm-3-5.4×1015cm-3之间，迁移率在1.7-2.56×102 cm2v-1s-1范围。而在较低和较高的掺杂浓度时，锑掺杂氧化锌纳米线表现为n型导电特性。（3）开展了氧化锌同质结LED器件的研究。利用同质外延生长的氧化锌纳米线阵列LED器件开启电压为3.4 V，LED中心波长428 nm，在蓝光LED和光电子器件领域展现出具有重要的发展前景。