Influence of interaction between organic cation and inorganic unit in bi-based hybrid perovskites for photoelectronic properties.

With the increase of the passion on lead-free perovskites, more and more endeavor focused on halobismuthates. Here, we have introduced the -iodoaniline and -phenylenediamine into Bi-based hybrid materials, and two photoactive iodobismuthate named -phenylenediamine iodobismuthate (PDABI) and -iodoaniline iodobismuthate (PIDBI) were prepared. Their single structures, band gaps, thermostability and other properties were explored. The structure results revealed that they all have 1D BiI anion chains with edge-shared BiI octahedron. The DFT result revealed that PIDBI had an inherent interaction between the I substituent in -iodoaniline cation and the Bi atom in inorganic BiI anion chains. The photodetector assembled by PDABI and PIDBI revealed that the interaction provided by symmetric -phenylenediamine has a positive effect on PIDBI's optoelectronic properties compared to the role of asymmetric -iodoaniline in PDABI.