장단기 파견

[단기연수] 210315 - 210319 APS MARCH MEETING 2021 (온라인) 1
2021-04-07 16:13:49 조회수420

1. 연수기간 : 2021. 03. 15 ~ 2021. 03. 19 (총 4박 5일) 

2. 연수국가 : 온라인 진행

3. 연수기관명 : APS Physics

4. 연수자 : 석박사통합과정 11기 참여대학원생 1명 

5. 연수주제 : Pressure-Induced the Purification of Cs4PbBr6 from CsPbBr3 Impurity

    Lead halide perovskites have been of great interest due to their promising optoelectronic applications. While solution-based synthetic methods have been well developed, they often form mixtures of perovskites with several different phases, which cannot be easily purified by conventional purification methods. Here we report a high-pressure purification method of Cs4PbBr6 perovskite containing a trace amount of CsPbBr3. The synthesized bulk Cs4PbBr6 perovskites exhibit strong photoluminescence at λpeak = ~ 520 nm because of CsPbBr3 embedded in Cs4PbBr6. Our approach utilized that CsPbBr3 crystals are sensitive to the change of pressure and make distortion of Pb-Br bonds at moderately low pressure, while Cs4PbBr6 crystals are much stable at high-pressure condition. With the application of high pressure (20 GPa), the crystalline CsPbBr3 phase turns amorphous while the crystal structure of Cs4PbBr6 is retained without change. Almost 95% of the CsPbBr3 phase can be removed by one cycle of compression. Cs4PbBr6 which originally shows strong green fluorescence becomes non-fluorescent after one cycle of compression. High-pressure compression can be used to selectively remove CsPbBr3 by pressure-induced amorphization without depreciating the Cs4PbBr6 crystal structure.

5.JPG 

 

 

 
사이트맵 닫기