ABSTRACT: Defects in crystalline materials, either intrinsic or extrinsic, play an important role in the performance of optoelectronic materials, and thus defect engineering has long been adopted as a powerful tool for tuning the properties of targeted material systems. Intrinsic point defects, such as atomic vacancies, antisite defects, and interstitial defects, can introduce intrinsic structural disorder, which can significantly affect the carrier recombination process and the stability of materials and devices. Extrinsic defects, like doping of foreign ions into a matrix, has been enabled us to master semiconductor technology by controlling over the type (p or n) and density of electrical carriers (electrons or holes) in microelectronics and optoelectronics. The arguably most stunning example that originates from the elaborate control of dopants is doped silicon, which forms the foundation of present-day microelectronics; the other example is doping various metal ions into the present-day widely studied halide perovskites,[1,2] which enables the discovery of some unusual optoelectronic properties. Intentional exploitation of defect engineering for fine-tuning the optoelectronic properties also involves the creation of some unconventional coordination geometry in metastable phases to produce unusual optically active centers. In this talk, I will report our experimental and theoretical works regarding the use of defect engineering to design and synthesize a range of optoelectronic materials including halide perovskites, [1-6] bismuth-activated near infrared luminescent materials, and UVC persistent phosphors.
- Y. Zhou, J. Chen, O. M. Bakr, and H.-T. Sun, Chem. Mater. 2018, 30, 6589−6613.
- Z. Yong, S. Guo, J. Ma, J. Zhang, Z. Li, Y. Chen, B. Zhang, Y. Zhou, J. Shu, J. Gu, L. Zheng, O. M. Bakr, H.-T. Sun, J. Am. Chem. Soc. 2018, 140, 9942-9951.
- B. Zhang, S. Yuan, J. Ma, Y. Zhou, J. Hou, X. Chen, W. Zheng, H. Shen, X. Wang, B. Sun, O. M. Bakr, L.-S. Liao, and H.-T. Sun, J. Am. Chem. Soc. 2019, 141, 15423-15432.
- Q. Liu, J. Yin, B. Zhang, J. Chen, Y. Zhou, L. Zhang, L. Wang, Q. Zhao, J. Hou, J. Shu, B. Song, N. Shirahata, O. M. Bakr, O. F. Mohammed, and H.-T. Sun, J. Am. Chem. Soc. 2021, DOI: 10.1021/jacs.1c01049.
- J. Ma, J. Yin, Y. Chen, Q. Zhao, Y. Zhou, H. Li, Y. Kuroiwa, C. Moriyoshi, Z. Li, O. M. Bakr, O. F. Mohammed, and H.-T. Sun, ACS Mater. Lett. 2019, 1, 185-191.
- J. Ma, J. Chen, J. Yin, B. Zhang, Q. Zhao, Y. Kuroiwa, C. Moriyoshi, L. Hu, O. M. Bakr, O. F. Mohammed, and H.-T. Sun, ACS Mater. Lett. 2020, 2, 367-375.
- B. Liu, Z. Zhang, K. Zhang, Y. Kuroiwa, C. Moriyoshi, H. Yu, C. Li, L. Zheng, L. Li, G. Yang, Y.Zhou, Y. Fang, J. Hou, Y. Matsushita, H.-T. Sun, Angew. Chem. Int. Ed. 2016, 55, 4967-4971.
- Y. Yang, Z. Li, J. Zhang, Y. Lu, S. Guo, Q. Zhao, X. Wang, Z. Yong, H. Li, J. Ma, Y. Kuroiwa, C. Moriyoshi, L. Hu, L. Zhang, L. Zheng, H.-T. Sun, Light: Science & Applications 2018, 7, 88.
BIOGRAPHY: Dr. Hong-Tao Sun is currently a Principal
Researcher at Nanoparticle Group, International Center for Materials
Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS),
Japan. He received his Ph.D. degree in Materials Science from Chinese Academy
of Sciences. Before joining NIMS, Dr. Sun worked as a Professor in Soochow
University, China, and led a group of Inorganic Chemistry and Optoelectronic
Materials. His current research interests include synthetic chemistry and
defect chemistry of colloidal nanocrystals, the structure-property
relationships of functional materials, and the applications of emerging
materials for LEDs, solar cells and biomedicine. The accomplishments of Dr. Sun
have resulted in more than 130 articles, and a number of these papers are
published in high impact scientific journals including JACS, Angew. Chem., and Light:
Science & Applications.