Research Projects

The rapid advancement of next-generation technologies such as wearable electronics, soft robotics, biomedical sensors, and flexible displays has intensified the demand for intrinsically stretchable optoelectronic materials. These materials must retain their optical and electronic functionality under repeated mechanical deformations, including stretching, bending, and twisting. Although flexible light-emitting devices have seen notable progress, the development of stretchable perovskite light-emitting diodes (PeLEDs) remains in its infancy due to challenges at the material interface. Among emerging candidates, inorganic perovskite nanocrystals—particularly cesium lead bromide (CsPbBr₃)—are highly promising due to their outstanding photoluminescence quantum yield (PLQY), narrow emission bandwidth (~20 nm), color tunability, and facile solution-processability. However, their intrinsic brittleness and poor compatibility with elastomeric substrates limit their stretchability and mechanical robustness. Phase separation, nanocrystal aggregation, and degradation under mechanical stress further hinder device performance. To address these issues, this project proposes a systematic strategy that integrates nanocrystal surface chemistry, polymer design, and mechanical–optical evaluation. The project will focus on synthesizing CsPbBr₃ nanocrystals capped with zwitterionic ligands designed to improve both colloidal stability and interfacial adhesion to polymer matrices. These ligands help prevent aggregation and maintain high PLQY under strain. Parallel to this, biocompatible, stretchable polymer hosts based on sodium alginate (SA) and custom-designed zwitterion-functionalized polymers will be developed. SA, a naturally derived polysaccharide, offers renewability, cost-effectiveness, and ionic functionality for enhanced mechanical integrity and dispersion of nanocrystals. Blending SA with oxidized PEDOT will improve conductivity and device performance. To further optimize conductivity, PEDOT-polymer blends will undergo secondary solvent doping with additives like ethylene glycol or DMSO, which are known to enhance charge transport. This strategy aims to produce robust, conductive, and highly elastic emissive layers capable of maintaining performance under 10–100% strain. Over the three-year project, the team will synthesize zwitterion-passivated CsPbBr₃ nanocrystals, design and characterize elastomeric polymer matrices, optimize PEDOT blends, fabricate stretchable nanocomposite emissive layers, and evaluate performance metrics under mechanical stress. Prototype PeLED devices will be fabricated via techniques such as spin-coating and inkjet printing. Key performance indicators—luminance, current efficiency, external quantum efficiency (EQE), and operational durability—will be benchmarked under static and dynamic mechanical loads. The effect of strain on optical output and device longevity will be systematically assessed. The expected outcomes include the creation of high-performance stretchable emissive materials with enhanced PLQY retention, improved nanocrystal dispersion, and reliable electroluminescence under mechanical deformation. The project will lead to PeLED prototypes with long-term stability and pave the way for wearable displays, electronic skin, and stretchable biosensors. Additional deliverables include insights into structure–property relationships in perovskite–polymer systems, high-impact publications, potential patentable technologies, and contributions toward sustainable optoelectronic materials. In conclusion, this multidisciplinary project brings together chemistry, materials science, and device engineering to address critical challenges in stretchable PeLED development. Through innovations in ligand engineering, polymer matrix design, and device architecture, it aims to realize durable, efficient, and eco-friendly stretchable light-emitting systems for future soft electronic applications.