Sb、Cu高浓度掺杂ZnO纳米阵列的白光与波长可调可见光LED的定量研究

Some problems such as defects and strains in film optoelectronic devices can be solved by using one dimensional (1D) nanostructures since they can provide new strategy and material platform due to their special characteristics in physics and chemistry. Since phosphor powders are overused for present GaN based white LED, we hope to overcome this weak point and obtain white and visible LED with no-phosphor, high efficiency, low working voltage and adjustable color temperature. In our research, we will fabricate pn hetero-junctions of ZnO nanoarrays with high Sb, Cu doping concentration on GaN film; we will quantitatively study the control mechanism of the Sb, Cu doping concentration, the device microstructure and the imposed bias voltage on the concentration of carries, energy levels, internal build-in electric field, conduct (valence) -band offset and movement of light emission wavelength. This research will take advantages of 1D nanostructure in doping and carries transport, solve the problems in band gap engineering, unstable p-type doping and the low density and mobility of carriers, quantitatively reveal the mechanism of white and visible light emission in ZnO/GaN LED, and grasp the core technology of new type white and visible LED in the end.

一维纳米结构体系的独特物理和化学性质有望解决传统薄膜光电器件中缺陷、应力等难以解决的问题，为光电器件的发展提供新的物质载体与思路。鉴于当今GaN基的白光LED过分依赖荧光粉调节，本项目拟克服此缺点，研制出无需荧光粉调节的、高效的、低电压工作的色温可调型白光和波长可调的可见光LED器件。通过对一维纳米ZnO阵列进行高浓度的Sb、Cu掺杂，构造ZnO纳米阵列/GaN薄膜基底的异质pn结；定量研究材料的高掺杂浓度、器件微结构和外加电压对材料载流子浓度和迁移率、器件中材料能级、内建电场、导（价）带能级差的调控和发射光波长偏移等的影响。本研究将发挥一维纳米结构在掺杂和载流子输运方面的优势，采用理论和实验结合方法，通过定量掺杂来解决ZnO纳米线中能级跃迁难调控、p型掺杂不稳定和载流子浓度与迁移率低的问题, 探索ZnO白光和可见光的发射机理，掌握新型白光和可见光LED的核心技术。

一维纳米结构体系的独特物理和化学性质有望解决传统薄膜光电器件中缺陷、应力等难以解决的问题，为光电器件的发展提供新的物质载体与思路。鉴于当今GaN基的白光LED过分依赖荧光粉调节，本项目拟克服此缺点，研制出无需荧光粉调节且无紫外光成分的、高效可低电压工作的色温可调型白光和波长可调的可见光LED器件。.本项目通过LPCVD法，在GaN基底上实现高质量、大面积、取向有序的Sb、Cu高浓度掺杂的图案化ZnO纳米线阵列的可控制备。采用原位阴极光谱（CL）技术，研究单根纳米线的发光特性。结合低温PL谱和常温PL谱技术，探究出高掺杂浓度对能级的调控关系。对单根掺杂ZnO异质结纳米线，利用透射电镜的原位全息电子显微术研究内建电场区域在外加电压下的宽度变化与电荷积累密度变化，确认电压调控电致发光波长的机制。研制出由Sb、Cu掺杂浓度、纳米线长度和外加电压调控的、在低电压下工作波长可调可见光发光二极管(LED)。但在低压下实现图案化ZnO纳米阵列的白光LED的难点未能充分解决。同时此项目还通过化学气相沉积法构建NiO/单层MoSe2 p-n结结构的红外光LED，稀土元素Yb/Er共掺杂的双层WSe2/MoSe2 LED等二维材料LED；以及锰离子掺杂的CsPbBr3纳米晶构筑的粉色钙钛矿LED。为进一步研究新型二维材料的光电性质，本项目也研究了石墨烯/钙钛矿、MXenes/Si、MXenes/MoS2和Au/MoS2等复合结构为基础的光电探测器。.本研究发挥了一维纳米结构在掺杂和载流子输运方面的优势，采用理论和实验结合方法，通过定量掺杂来解决ZnO纳米线中能级跃迁难调控、p型掺杂不稳定和载流子浓度与迁移率低的问题，探索ZnO白光和可见光的发射机理，掌握新型白光和可见光LED的核心技术，并推广到二维材料型LED和钙钛矿型LED等新型发光器件及光电探测器的应用领域中。