Exploring The Coexistence Mechanism Of Cspb2br5 And Cspbbr3 Based On The Competitive Phase Diagram

A new layered material CsPb2Br5 with great stability and excellent optoelectronic properties has attracted great attention. At present, the luminescent mechanism of CsPb2Br5 is a hot topic. Last year, a theoretical work reports that the green light of CsPb2Br5 is caused by V-Br and Cs-Pb defects in the material. But soon after, an experimental article overturned it. According to the experiment, the coexistence phenomenon of CsPb2Br5 and CsPbBr3 provided a reasonable explanation for the CsPb2Br5 emitting green light. However, the coexistence mechanism of CsPb2Br5 and CsPbBr3 is still unclear. The dispute about the luminescent mechanism of CsPb2Br5 cannot be clarified fundamentally. Using the density functional theory calculation, we explored the coexistence mechanism with the competitive phase diagram in this paper. On the basis of the coexistence of CsPb2Br5 and CsPbBr3, the mechanism of CsPb2Br5 emitting green light is also studied. The paper theoretically verified the relevant experiments and clarified fundamentally the dispute about the luminescent mechanism of CsPb2Br5.