Wang Zhongwu, Lin Hongzhen, Zhang Xi, Li Jie, Chen Xiaosong, Wang Shuguang, Gong Wenbin, Yan Hui, Zhao Qiang, Lv Weibang, Gong Xue, Xiao Qingbo, Li Fujin, Ji Deyang, Zhang Xiaotao, Dong Huanli, Li Liqiang, Hu Wenping
Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China.
Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China.
Sci Adv. 2021 Apr 14;7(16). doi: 10.1126/sciadv.abf8555. Print 2021 Apr.
Interface stresses are pervasive and critical in conventional optoelectronic devices and generally lead to many failures and reliability problems. However, detection of the interface stress embedded in organic optoelectronic devices is a long-standing problem, which causes the unknown relationship between interface stress and organic device stability (one key and unsettled issue for practical applications). In this study, a kind of previously unknown molecular conformation-induced stress is revealed at the organic embedded interface through sum frequency generation (SFG) spectroscopy technique. This stress can be greater than 10 kcal/mol per nm and is sufficient to induce molecular disorder in the organic semiconductor layer (with energy below 8 kcal/mol per nm), finally causing instability of the organic transistor. This study not only reveals interface stress in organic devices but also correlates instability of organic devices with the interface stress for the first time, offering an effective solution for improving device stability.
界面应力在传统光电器件中普遍存在且至关重要，通常会导致许多故障和可靠性问题。然而，检测有机光电器件中嵌入的界面应力是一个长期存在的问题，这导致了界面应力与有机器件稳定性之间的关系不明（这是实际应用中的一个关键且未解决的问题）。在本研究中，通过和频产生（SFG）光谱技术在有机嵌入界面揭示了一种前所未知的分子构象诱导应力。这种应力每纳米可大于10千卡/摩尔，足以在有机半导体层中诱导分子无序（每纳米能量低于8千卡/摩尔），最终导致有机晶体管不稳定。本研究不仅揭示了有机器件中的界面应力，还首次将有机器件的不稳定性与界面应力相关联，为提高器件稳定性提供了有效解决方案。
