High-performance flexible Cs2AgBiBr6 photodetector by using transferable TiO2 nanorod electron-transport layer

Abstract

The Electron Transport Layers (ETL) are an essential component for high performance perovskite optoelectronic device to promote the overall charge extraction efficiency and tune the crystallinity of the perovskite layer. Among a series of efficient metal oxide ETL, such as TiO2, ZnO, and SnO2, one-dimensional TiO2 nanorods (NRs) provide a crucial function in extracting and transporting photogenerated electrons and minimizing charge recombination in perovskite photodetector (PD).

However, TiO2 NRs are often grown or deposited on rigid substrates, which hinders the broad application area. Considering this factor, I demonstrated the chemical lift-off (CLO) method to develop highly efficient transferable TiO2 NRs to be fabricated as an interlayer property of a flexible perovskite photodetector. I observed a TiO2 NRs -based flexible Cs2AgBiBr6 PD operating wavelength of 405nm under an external bias voltage of 0.5V with an outstanding on/off ratio of 103, photoresponsivity (R) of 76 mA, and a detectivity (D*) of 1.98 x ×1012. The PD performance is stable under bending cycles with a radius of 1cm up to 300 times. The demonstrated transferable TiO2 NRs based on flexible perovskite PD is a step forward in merging mature compound semiconductor technology and flexible optoelectronic device with simple structure and high performance for a stable bending state.