The phonon-assisted up-conversion photoluminescence in halide perovskites

Sheng-Chan Wu^1*, Shao-Zhi Wu², Li-Chung Tsai³, Cheng-Chieh Wu³, Meng-Cheng Yen⁴, Chia-Kai Lin², Yi-Fang Ting², Hsin-Ming Cheng², Ya-Ju Lee^2,4, Pai-Chun Wei³, Hsu-Cheng Hsu^2,4

¹Photonics, National Sun Yat-sen University, Kaohsiung, Taiwan
²Photonics, National Cheng Kung University, Tainan, Taiwan
³Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan
⁴Program on Key Materials, Academy of Innovative Semiconductor and Sustainable Manufacturing, National Cheng Kung University, Tainan, Taiwan

* Presenter:Sheng-Chan Wu, email:scwu@mail.nsysu.edu.tw

Halide perovskites have attracted tremendous research and engineering attention in solid-state lighting and solar cells. However, their well-known poor thermal conductivity may hinder potential device applications, as thermal effects typically degrade performance. Interestingly, perovskites also exhibit special phonon-assisted up-conversion photoluminescence characteristics. This process provides a channel to deplete phonons from the system while simultaneously generating light. In this talk, nearly resonant excitation of exciton-polaronic states in the 2D perovskite (PEA)₂PbI₄ is demonstrated to produce phonon-assisted up-conversion photoluminescence at room temperature. Net optical cooling from room temperature via this anti-Stokes process is observed. This finding highlights the potential applications for optical refrigeration.

Keywords: halide perovskites, phonon-assisted up-conversion photoluminescence