| Hundreds of millions of years of natural selection have created a variety of highperformance biological materials.The unique and excellent properties of biological materials are closely related to their crystallization mineralization process and multilevel ordered structure,which can provide us with a good source of inspiration when designing and preparing high-efficiency functional optoelectronic devices.The efficient and stable operation of perovskite light-emitting diode(PeLED)not only affects human production and life,but also plays a significant role in the country’s goal of carbon neutrality and the development of a low-carbon economy.However,the defects in the key functional materials of the device will restrict the efficiency of the device;external environmental factors will seriously affect the stable operation of functional optoelectronic devices.Therefore,continuous optimization of the performance of key materials in light-emitting dioides is particularly important for the development of advanced light-emitting and energy-storage devices.Learning from nature:the crystallization and mineralization process of biological materials can provide us with new ideas for the preparation of efficient functional optoelectronic devices;the cross-scale multi-level mechanical structure design of biological materials can give us the ability to maintain the safety and stability of functional optoelectronic devices.Therefore,this paper will improve the efficient and stable operation of advanced light-emitting display from two aspects:the biomimetic crystallization of functional optoelectronic materials and the design of biomimetic multi-level mechanical structures.The specific research content included is summarized as follows:1.Metastable phase crystallization for planar-defect PeLED.Intragrain Ruddlesden-Popper(RP)-type planar defects were identified by atomically resolved spherical aberration electron microscopy,which is due to lattice strain caused by inhomogeneous halide ion distribution.The existence of such planar defects will generate defect states at the band edge of perovskite,and will generate multi-band gap exciton recombination behavior inside the film,affecting the luminescence performance and color purity.In order to eliminate these RP-type defects,inspired by the biomineralization,we propose a metastable phase crystallization strategy,which can effectively reduce the lattice stress inside the perovskite nanocrystals,and thus obtain high quality CsPbI3-xBrx thin films without planar defects with improved Radiative recombination,narrow emission bands,and enhanced spectral stability.Using these high-quality thin films,we fabricate spectrally stable pure red PeLEDs,showing 17.8%external quantum efficiency and 9000 cd m-2 brightness with color coordinates required by Rec.2020.2.Biomimetic strong passivation molecular design for fabricating lattice-anchored PeLED.Moreover,inspired by the strong interactions between proteins and biominerals,we developed a sulfonyl ligand molecule that has a strong coordination effect with the perovskite crystal.Only with addition of a single ligand molecule can effectively control the metastable phase crystallization process of all-inorganic CsPbI3-xBrx,and finally fabricate the highly-oriented and planar defect-free perovskite film showing high luminescence and high lattice stability.Using this high quality film,the pure red PeLED exhibited an external quantum efficiency of more than 16%,a brightness of up to 20000 cd m-2 and T50 more than 10 h under 100 cd m-2.3.A nacre inspired coating for impact-tolerant PeLEDs.Inspired by the nacre ordered structure of "brick and mud" and the impact resistance enhanced by residual stress,we constructed a coating with an nacre-like ordered structure by scraping the scraper method and further developed a prestressing strategy to increase the energydissipating areas in the coating.From the analysis results of the ball impact test and finite element simulation,it can be known that the impacted bioinspired nacre-like coating will dissipate the impact stress during the sheet slip process,which provides a new idea for maintaining the stable operation of functional optoelectronic devices. |
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