NSRRC Activity Report 2023

Soft Matter 041 TLS 23A1 Small/Wide Angle X-ray Scattering • GIWAXS and GISAXS • Chemistry, Materials Science, Interface and Thin-film Chemistry, Condensed-matter Physics References 1. K. Lin, J. Xing, L. N. Quan, F. P. G. de Arquer, X. Gong, J. Lu, L. Xie, W. Zhao, D. Zhang, C. Yan, W. Li, X. Liu, Y. Lu, J. Kir- man, E. H. Sargent, Q. Xiong, Z. Wei, Nature 562 , 245 (2018). 2. H. Cho, S.-H. Jeong, M.-H. Park, Y.-H. Kim, C. Wolf, C.-L. Lee, J. H. Heo, A. Sadhanala, N. Myoung, S. Yoo, S. H. Im, R. H. Friend, T.-W. Lee, Science 350 , 1222 (2015). 3. C. Yi, J. Luo, S. Meloni, A. Boziki, N. Ashari-Astani, C. Gratzel, S. M. Zakeeruddin, U. Rothlisberger, M. Gratzel, Energy Environ. Sci. 9 , 656 (2016). 4. M. Hao, Y. Bai, S. Zeiske, L. Ren, J. Liu, Y. Yuan, N. Zarrabi, N. Cheng, M. Ghasemi, P. Chen, M. Lyu, D. He, J.-H. Yun, Y. Du, Y. Wang, S. Ding, A. Armin, P. Meredith, G. Liu, H.-M. Cheng, L. Wang, Nat. Energy 5 , 79 (2020). 5. F.-C. Liang, F.-C. Jhuang, Y.-H. Fang, J.-S. Benas, W.-C. Chen, Z.-L. Yan, W.-C. Lin, C.-J. Su, Y. Sato, T. Chiba, J. Kido, C.-C. Kuo, Adv. Mater. 35 , 2207617 (2023). P hotonic integrated circuits (PICs) that integrate multiple photonic components have emerged as promising candidates for applications in big data databases with high speed, large integration capacity, and low thermal effects. There is a pressing need to explore corresponding photonic components such as lasers, optical waveguides, optical modulators, photodiodes, and nonvolatile flash photomemories. Among these, nonvolatile flash photomemories exhibit photosensitive function and recording characteristics, which could further simplify the design of PICs. Organic–inorganic hybrid perovskites (OIHPs) materials have been applied to various optoelectronic devices owing to their outstanding semiconducting properties, solution-processable characteristics, long exciton lifetime, and small binding energy. They have emerged as promising candidates for next-generation nonvolatile flash photomemory devices. A research team led by Jung-Yao Chen (National Cheng Kung University) demonstrated that the high interfacial area between the perovskite floating gate and charge-transporting material is the key factor in realizing ultrafast responsive photomemory, with a recorded lowest photo-programming time of 1 ms. 1−2 Recently, room-temperature phosphorescence 2D OIHP received considerable attention owing to its long- lived triplet excitons for potential applications, elevating the performance of optoelectronics. 3−4 However, thus far, systematic engineering of the exciton lifetime of 2D OIHP Exploring Novel Directions for Improving Optoelectronic Devices Triplet–triplet dexter energy transfer between the inorganic layer and organic cation in 2D organic and inorganic hybrid perovskites (OIHPs) enhances the performance of the derived photomemory. for enhanced photomemory performance is still limited. To leverage the effect of exciton lifetime on the performance of photomemory, two 2D OIHPs, 2-phenylethylammonium lead bromide ((PEA) 2 PbBr 4 ) and 4-biphenylmethylammonium lead bromide ((BPMA) 2 PbBr 4 ), are spatially confined in polystyrene- block -poly(ethylene oxide) (PS- b -PEO), serving as photoactive floating gates with p -type semiconductor poly(3-hexylthiophene-2,5-diyl) (P3HT) as the charge- transporting material in nonvolatile floating-gate photomemory. Grazing-incidence small-angle scattering (GISAXS) at TLS 23A1 was employed to confirm self- assembling microphase separation in PS- b -PEO/2D OHIP composite films, as shown in Figs. 1(c) and 1(d) . 2D diffraction patterns ( Figs. 1(e) and 1(f) ) from grazing- incidence wide-angle scattering (GIWAXS) at TPS 25A confirm the formation of 2D OIHPs in composite films. By triggering the energy transfer between inorganic parts and organic cations and extending the conjugated length of organic cations, an extremely low photo-programming time of 0.7 ms, multilevel behavior of a minimum of 7 bits (128 levels), remarkable photosensitivity of 19.10 AW -1 , and significant low power consumption of 6.79 × 10 -8 J per bit can be achieved. The present study provides a new perspective on the function of triplet excitons in nonvolatile photomemory. (Reported by Jung-Yao Chen, National Cheng Kung University)