CsPbX3(X=I,Br,Cl)钙钛矿量子点/纳米ZnO复合体系的制备及高效率高显色性白光的研究

Quantum dots (QDs) based white light emitting diode (LED) is the most attractive hot point in current study of white emitters, since it could produce high efficiency and high color rendering white light in a monolithic chip. Notably, CsPbX3 (X = I, Br, Cl) QDs, as a new class of all-inorganic lead halide perovskites, offers the advantages such as high quantum yields, high optical gains and being largely free from mid-gap trap states. In this project, we would conduct a research of white light material and emitter based on CsPbX3 QDs/nano-ZnO complex. The main job contents are shown as follows: the nucleation and growth kinetics of CsPbX3 QDs would be investigated in detail, and their band gaps would be tuned by the quantum size effect and the composition variation based on energy band engineering, aiming to realize wavelength-tunable emissions covering the whole visible spectra and high quantum yield tricolor luminescence; CsPbX3 QDs/(0D&1D) nano-ZnO complex would be designed and prepared then, revealing the effect of nano-ZnO on color rendering, luminescence efficiency and optical gains of the complex materials. Besides, the recombination mechanism of stimulated emissions from CsPbX3 QDs would be studied particularly, to realize high efficiency and high color rendering white luminescence as well as random lasing; the prototype lighting emitting devices would be constructed based on CsPbX3 QDs/nano-ZnO complex, carefully analyzing the effect of dimensions of nano-ZnO on carrier transport and light extraction efficiencies, to realize high quality and low threshold electrically driven white luminescence and random laser. Totally, this project would explore a new route in the study of white material and emitter, which belongs to the key object in optoelectronics and information field.

量子点白光LED可实现单芯片三基色复合白光，改善显色性的同时有利于提高器件效率，是当前白光LED研究的热点。新型钙钛矿材料CsPbX3(X=I，Br，Cl)量子点具有高量子产率、无带间缺陷态、高光学增益等优点。本课题拟基于CsPbX3量子点/纳米ZnO复合体系开展白光材料和器件的研究：探究CsPbX3量子点成核和生长的动力学过程，通过量子尺寸效应和能带工程组分调制两种途径，实现覆盖可见光波段、波长可调的发光和高量子产率三基色发射；构建CsPbX3量子点/（零维、一维）纳米ZnO复合材料体系，揭示ZnO对显色性、发光效率和光学增益的影响，重点探究CsPbX3量子点受激发射的复合机制，实现高效率高显色性白光和随机激光；构建原型器件，揭示ZnO维度对载流子输运和光萃取效率的影响，实现高品质低阈值的电注入白光和随机激光。本课题探索了白光材料和器件研究的新途径，是光电子材料和信息领域的前沿课题。

量子点材料和器件已成为半导体发光领域的研究热点。全无机铯铅卤化物CsPbX3(X = I, Br, Cl)钙钛矿量子点材料具有高荧光量子产率、荧光寿命短和波长连续可调等优异的光学性质。本课题基于CsPbX3量子点&纳米ZnO材料体系开展了半导体发光材料和器件研究。.主要研究内容和成果包括：(1) 采用热注射等方法可控合成CsPbX3钙钛矿量子点，实现了高效的三基色量子点荧光和光泵浦钙钛矿量子点随机激射。(2) 采用量子点作为激活层，设计构建p-i-n结LED器件，但载流子注入型器件中CsPbX3钙钛矿量子点的荧光效率很低。进而采用ZnO纳米线阵列同时作为光波导和n型层，旋涂覆盖CsPbBr3量子点作为荧光层，有效的激发了钙钛矿量子点荧光，荧光转换效率可达到41.6 %，实现了荧光转换白光LED原型器件。(3) 为获得更高效的短波长激发源，基于纳米氧化锌体系，设计构建了一系列电泵浦随机激光原型器件。基于GaN基片异质外延，构建了Au/MgO/ZnO MIS异质结发光原型器件，实现了纯净的紫外电致发光和随机模式的电泵浦激射；基于多晶岛状纳米氧化锌薄膜，在硅衬底上直接集成了低阈值的激子型紫外随机激光二极管器件，实现了一种自下而上的氧化锌基集成光电子器件的新思路；将MIS结器件成功的移植到了锌箔衬底上，实现了ZnO的柔性激光器件，器件兼具了忆阻的存储功能，实现了单一芯片上光学器件和电子器件功能的集成。(4) 针对CsPbX3钙钛矿量子点激光器件的困难和载流子注入型、荧光转换型发光器件的调制带宽限制，开展了电子束泵浦钙钛矿量子点随机激光研究，创新的设计实现了一种电真空半导体激光器件。基于微通道光电倍增机构，设计构建了可高速调制的真空电子束泵浦源；倍增后的电子束聚焦轰击 CsPbBr3量子点荧光层表面，实现了高效率的荧光发射和电子束泵浦随机激射。.本项目研究拓展了白光材料和器件研究的途径，探索实现了具有优异光电响应特性的电真空半导体激光器件的新思路，在发光材料、照明显示和可见光通信等领域具有重要意义和潜在应用空间。