Feng Yan

Perovskite & Organic devices


Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong




Email: apafyan@polyu.edu.hk



Prof. Feng Yan received his Ph.D. degree in physics from Nanjing University in, 1997 and has been an associate professor of Physics at Nanjing University since January 2001. He joined the Department of Engineering, University of Cambridge as a research Fellow in February 2001. He joined NPL in April 2006 as a Senior Research Scientist. He was appointed assistant Professor in the Department of Applied Physics of the Hong Kong Polytechnic University in September 2006 and was promoted to full Professor in 2016. His research interests include organic electronics, two-dimensional materials, solar cells, thin film transistors, biosensors and smart materials.

Abstract for Presentation

Strategies for achieving high-performance Sn-based perovskite solar cells


Tin-based  perovskites  are  promising  candidate  materials  for  efficient  lead-free perovskite  solar  cells  (PSCs)  due  to  their  excellent  optoelectronic  properties  and suitable bandgaps. However, it is challenging to prepare highly stable and efficient tinbased  PSCs  because  Sn2+  in  perovskites  can  be  easily  oxidized  to  Sn4+  upon  air exposure.  Many  effective  approaches  have  been  developed  to  improve  the  device performance and a power conversion efficiency of over 14% has been achieved. In this talk,  I  will  introduce  the  fabrication  of  air-stable  FASnI3  PSCs  by  adding hydroxybenzene sulfonic acid or gallic acid as antioxidant agents into the perovskite precursor solution along with excess SnCl2. The interaction between the additives and SnCl2  promote  their  homogenous  dispersion  in  the  perovskite  film.  Moreover,  the strong  antioxidant  capacity  of  the  additives  enables  enhanced  oxidation  stability  of FASnI3. The corresponding PSCs can maintain 80% of the efficiency over 1000 h upon air exposure without encapsulation, which is over ten times longer than the best result reported before.   Our results suggest a novel strategy for the design of efficient and stable tin-based PSCs.


[1] J. P. Cao, H.-L. Loi, Y. Xu, X. Guo, N. Wang, C. K. Liu, T. Wang, H. Y. Cheng, Y. Zhu, M. G. Li, W. Y. Wong, Feng Yan*, Adv. Mater. 34, 2107729 (2022).

[2] J Cao, Feng  Yan*, Energy Environ. Sci. 14 (3), 1286-1325, (2021).

[3]  Q Tai, X Guo, G Tang, P You, TW Ng, D Shen, J Cao, CK Liu, N Wang, Ye Zhu, Chun-Sing Lee, Feng YAN*, Angew. Chem.-Int. Edit. 58, 806-810 (2019).