From Bright but Fragile to Ceramic-Stable and Printable: Professor Liang Li’s Quantum-Dot Innovation Journey

Overview: The Real Problem Is Survival

Quantum dots and perovskite nanocrystals have long been regarded as ideal light-emitting materials. They offer high color purity, strong absorption, narrow emission, and solution processability—qualities that make them attractive for displays, lighting, bioimaging, security printing, and radiation-activated medical materials. But Professor Liang Li’s innovation journey begins with a practical question: if quantum dots are so optically powerful, why are they still difficult to use in real devices?

The answer is stability. As highlighted in Professor Li’s presentation, quantum dots are fragile under heat, moisture, oxygen, light, and electrical stress. In on-chip display architectures, especially micro-LED color conversion, these stresses become even more severe. Small pixels require fine patterning; long-life devices require operational stability; and manufacturing requires inks or dispersions that remain processable. The target is therefore ambitious: quantum-dot-level optical performance, ceramic-phosphor-level stability, and solution processability in one material platform.

 

Timeline of the Innovation Journey

Period	Milestone	Core advance
2015	Aluminum self-passivation	Turning oxidation into protection
2016–2017	Waterless silica and silica/alumina encapsulation	Protecting perovskite quantum dots in oxide matrices
2019	Sacrificial oxidation	Actively growing protective oxide layers on quantum dots
2020–2021	High-temperature confined synthesis	Growing and sealing perovskite nanocrystals inside inorganic hosts
2021–2022	Display tuning and thermal-quenching suppression	Making protected nanocrystals meet LED/display requirements
2023	Solution-processable CsPbBr3–SiO2 nanospheres	Combining dense sealing with micro-LED patternability
2026	Framework-anchored potassium and mesopore-selective sintering	Low-temperature ceramic-like encapsulation without particle fusion

2015: Turning Degradation into Protection

The first milestone came from a simple but powerful idea: use oxidation as a protective mechanism rather than treating it only as degradation. By doping conventional quantum dots with aluminum, Professor Li’s team showed that aluminum in the shell could oxidize into an alumina-like layer, forming a self-passivating barrier [1], [2]. This thin inorganic layer improved photostability while preserving luminescence.

This was important because it established a guiding principle for the whole research cluster: fragile nanocrystals can survive harsh environments if their surfaces are protected by dense, inorganic barriers. The related patent portfolio also shows that this early self-passivation concept was translated into intellectual property, including patents on self-passivating quantum dots and their preparation methods.

2016–2019: From Self-Passivation to Oxide Encapsulation

The next challenge was perovskite quantum dots. These materials can be brighter and more color-pure than many traditional emitters, but they are highly sensitive to moisture, oxygen, heat, and processing chemicals. Professor Li’s team therefore moved from self-passivation to broader oxide encapsulation strategies.

In 2016, the team developed a “waterless” silica coating route in toluene to protect moisture-sensitive CH3NH3PbBr3 quantum dots [5]. This avoided the water-based chemistry that normally damages perovskites. In 2017, they advanced the approach with silica/alumina monoliths, using dual-oxide protection to improve barrier quality while maintaining high photoluminescence [6]. In 2019, they further introduced sacrificial oxidation, using a self-metal source to rapidly grow metal oxide layers on quantum dots [3].

These works proved that oxide barriers could greatly improve nanocrystal survival. However, they also revealed a limitation: room-temperature coatings and solution-processed oxides may still contain pinholes or porous pathways. For demanding on-chip display operation, the barrier must become denser—closer to ceramic protection.

2020–2021: A Paradigm Shift to High-Temperature Confined Synthesis

The decisive shift in Professor Li’s work was moving from “synthesize first, coat later” to “grow and encapsulate together.” Instead of preparing fragile colloidal quantum dots and then trying to protect them, the team began forming perovskite nanocrystals inside inorganic hosts at high temperature.

This direction began with melt crystallization in halide salts [7] and template-assisted solid-state synthesis at 800 °C [8]. The use of mesoporous alumina and silica templates allowed the pores to confine nanocrystal growth, preventing uncontrolled enlargement at high temperature. The major breakthrough came with ceramic-like CsPbBr3 nanocrystals encapsulated in silica derived from molecular sieve templates [9]. This material combined high brightness with exceptional stability, including 1000-hour on-chip operation and resistance to harsh acidic conditions.

This stage changed the logic of stabilization. The goal was no longer simply to coat a fragile nanocrystal. It was to create a protected composite particle from the beginning, using high-temperature solid-state chemistry similar to ceramic phosphor production.

2021–2022: From Stability to Display-Grade Performance

After solving much of the stability problem, the next question was performance under real display requirements. Professor Li’s team tackled several critical display bottlenecks.

For color quality, the team used band-gap engineering to tune CsPbBr3 nanocrystals toward the Rec. 2020 green-display standard [10]. For brightness and uniformity, they refined high-temperature confined synthesis to achieve stable and uniform CsPbBr3 nanocrystals with high quantum yield [11]. For LED operation, they addressed thermal quenching, a major reason why perovskite emitters lose efficiency under heat. Fluoride treatment and wide-bandgap surface-layer construction helped suppress temperature-induced emission loss [12], [13].

Together, these papers show that Professor Li’s research was not only about making nanocrystals stable. It was about making them stable, bright, spectrally precise, and thermally reliable for display and LED applications.

2023: Solving the Processability Bottleneck

A new problem then emerged. High-temperature encapsulation can produce ceramic-like stability, but it can also weld particles together. Aggregated powders are difficult to disperse, print, or pattern. This is a serious obstacle for micro-LED color conversion, where pixel patterns may be 20 μm or smaller.

In 2023, Professor Li’s team introduced potassium-assisted selective sintering to produce ultra-stable, solution-processable CsPbBr3–SiO2 nanospheres [14]. The innovation was to create a processing window where silica pores sealed densely, but individual particles did not fuse together. The resulting nanospheres were small, stable, dispersible, and suitable for photolithographic inks. This was a major step toward combining ceramic-like protection with micro-LED patternability.

The same silica-encapsulated perovskite platform also opened a biomedical direction. Under X-ray irradiation, silica-protected perovskite nanocrystals could generate singlet oxygen, suggesting possible use in radiation-activated therapeutic strategies [15].

2026: Mesopore-Selective Sintering as a General Platform

The latest milestone is framework-anchored potassium-enabled mesopore-selective sintering [16]. This work provides the deeper mechanism behind the platform. Instead of relying on global high-temperature sintering, framework-anchored potassium locally weakens Si–O bonds and enables pore collapse at lower temperature. This produces dense encapsulation while avoiding nanocrystal degradation and inter-particle fusion.

This is the key conceptual leap: ceramic-level protection no longer requires sacrificing solution processability. According to Professor Li’s materials, this platform can extend beyond CsPbBr3 to other nanocrystals and phosphors, supporting micro-LED color conversion, bioimaging, and other demanding applications.

A Platform, Not a Single Material

Across this decade-long journey, Professor Liang Li’s innovation can be summarized as the transformation of quantum dots from optically excellent but operationally fragile nanomaterials into ceramic-stable, solution-processable functional particles. The work progresses logically from aluminum self-passivation, to oxide encapsulation, to high-temperature confined synthesis, to display-grade tuning, and finally to printable ceramic-like nanospheres.

The significance is not only one better perovskite material. It is a broader materials platform: protect the nanocrystal, preserve its brightness, control its size, seal it densely, and keep it printable. That is the innovation pathway that connects the 16 papers, the patents, and Professor Li’s current technology story.

List of Patents Related to the Innovation Pathway

The patent portfolio provided by Professor Li supports the same innovation pathway described above: self-passivation, oxide/silica encapsulation, high-temperature confined synthesis, dense fluorescent composite particles, and application-oriented quantum-dot platforms. The list below follows the supplied patent directory.

No.	Patent / Invention Title	Inventor(s)	Patent No. / Application No.
1	一种基于陶瓷荧光复合颗粒的荧光探针的制备方法、应用	瞿奕辰, 李良, 郑玲玲, 张宇涵	2026101928072
2	半导体荧光复合颗粒及其制备方法	李良、何梦达、张庆刚、韦未雨、孔龙	ZL202211255720.3
2	荧光复合颗粒及其制备方法	李良、何梦达、张庆刚、韦未雨、孔龙	PCT/CN2023/124578
2	Fluorescent composite particles and preparation method therefor	李良、何梦达、张庆刚、韦未雨、孔龙	US20260117119A1
3	一种半导体复合发光材料、制备方法及发光器件	李良、郑为霖、何梦达、孔龙	ZL202111481852.3
4	半导体纳米晶荧光材料的制备方法以及通过所述方法制备的半导体纳米晶荧光材料及其应用	李良、张庆刚	ZL201911055146.5
4	Fluorescent semiconductor nanocrystal material, preparation and application thereof	李良、张庆刚	WO2021082096A1 / US11898072B2
5	一种钙钛矿复合发光材料及其制备方法、产品和应用	李良、汪波	CN202010839486.3
6	一种复合发光材料及其制备方法	李良、汪波	ZL201911377745.9
6	Luminescent composite material and preparation method therefor	李良、汪波	US12012538B2
7	金属氧化物/二氧化硅包覆或包裹的量子点及其制备方法	李良、李志春、黄寿强	ZL201610478181.8
7	Metal oxide/silicon dioxide-coated quantum dot and method for preparing same	李良、李志春、黄寿强	WO2018000704A1 / US10696900B2
8	一种荧光钙钛矿纳米晶及其制备方法和应用	李良、张从阳	ZL201710778351.9
11	一种自钝化量子点及其制备方法	李良、李志春	ZL201510830152.9
11	Self-passivating quantum dot and preparation method thereof	李良、李志春	WO2016086511A1 / US10377946B2

Note: Patent numbering follows the supplied directory; repeated numbers indicate related national, PCT, or US family members for the same invention direction.