Facet-engineered photo-induced charge transfer dynamics at the interface of cubic CsPbBr3 and organic acceptor molecules

Perovskite, particularly halide perovskite shows tremendous application in the field of optoelectronic devices such as Light emitting diode (LED) and solar cells. Semiconducting nanomaterials like perovskite nanomaterials have photoactive components and are used as electron as well as hole donors. A hybrid combination of organic acceptors such as Anthraquinone (AQ) and Tetracyanoquinodimethane (TCNQ) with CsPbX3 (X = Cl, Br, I) perovskite nanomaterials at the interface is a unique path for charge separation. The surface of the perovskite nanomaterial plays an important role in the electron-hole charge separation. The surface of the perovskite nanomaterial is responsible for the interaction between this redox couple. Only those molecules show better charge separation which interacts more efficiently with the excited state of the perovskite nanocrystals (PNCs), but very few organic molecules show this kind of redox properties. In the present study, we employed AQ and TCNQ to extract charges from PNCs. We performed photoluminescence (PL) and time-correlated single photon count spectroscopy (TCSPC) to investigate the impacts of both organic acceptor molecules on the lifetime and photoluminescence (PL) of PNCs. PNCs possessed distinct lifetime and luminous characteristics prior to and after the incorporation of quenchers, however, in the case of TCNQ, improved charge separation occurred, as evidenced by PL and TCSPC. We additionally employed SEM (scanning electron microscopy) and TEM (transmission electron microscopy) to investigate the influence of the quencher on morphology.

Automated summary

Perovskite, especially halide perovskite, shows great potential in optoelectronic devices. A combination of organic acceptors with perovskite nanomaterials can achieve charge separation, and the surface of the nanomaterials plays a crucial role in this process.