Tan Mingrui, Li Mingbian, Pan Wanting, Feng Xiaopeng, He Yuhong, Liu Junjun, Dong Fengxia, Wei Haotong, Yang Bai
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 130012, Changchun, China.
Optical Functional Theranostics Joint Laboratory of Medicine and Chemistry, The First Hospital of Jilin University, 130012, Changchun, China.
Light Sci Appl. 2022 Oct 18;11(1):304. doi: 10.1038/s41377-022-01000-6.
Quasi-2D perovskites have been demonstrated to be competitive materials in the photodetection fields due to the enhanced moisture stability by large organic cations. However, as the increasing demands of modern technology, it is still challenging to combine the flexibility with the capability of weak light detection in a low-cost way. Here, amides, carboxylic acids, and anhydrides groups-rich carbonized polymer dots (CPDs) were employed to fill in the perovskite grain boundaries, which can passivate the point defects of perovskite by coordinating with the unbonded Pb atoms, and reduce the leakage current. Weak light detection capability was demonstrated by directly resolving light with an intensity of 10.1 pW cm. More importantly, the stretchable polymer chains on CPDs strongly interact with perovskite ions through multiple supramolecular interactions, and extend the stretchable properties to the perovskite/CPDs composites, which can maintain the integral structure stability during the deformation of perovskite crystals and restricted any crack by releasing the film strain. Our fabricated devices show extraordinary flexible stability in the bending-dependent response tests. The viscoelasticity of CPDs improves the bending stability of the flexible quasi-2D perovskite photodetectors, and device performance shows no degradation after bending 10000 times, comparable or even outperforming the dominating flexible photodetectors.
由于大有机阳离子增强了湿度稳定性，准二维钙钛矿已被证明是光探测领域中有竞争力的材料。然而，随着现代技术需求的不断增加，以低成本方式将柔韧性与弱光探测能力相结合仍然具有挑战性。在此，富含酰胺、羧酸和酸酐基团的碳化聚合物点（CPD）被用于填充钙钛矿晶界，其可通过与未键合的Pb原子配位来钝化钙钛矿的点缺陷，并降低漏电流。通过直接分辨强度为10.1 pW/cm的光证明了弱光探测能力。更重要的是，CPD上的可拉伸聚合物链通过多种超分子相互作用与钙钛矿离子强烈相互作用，并将可拉伸性能扩展到钙钛矿/CPD复合材料，这可以在钙钛矿晶体变形期间保持整体结构稳定性，并通过释放薄膜应变来限制任何裂纹。我们制造的器件在弯曲相关响应测试中表现出非凡的柔韧性稳定性。CPD的粘弹性提高了柔性准二维钙钛矿光电探测器的弯曲稳定性，并且器件性能在弯曲10000次后没有下降，与主要的柔性光电探测器相当甚至更优。
