Effect of organic spacer cations on the stability of organic-inorganic hybrid perovskite thin film transistors

Organic-inorganic halide perovskites have been widely used for thin film transistors (TFTs), which is due to their excellent properties and flexible preparation capabilities. For TFTs, having flexible preparation capabilities is crucial because it allows researchers to optimize the perovskite material for desired electrical performance, stability, and compatibility with other components in the device. However, the stability of organic-inorganic halide perovskite thin film transistors (TFTs) is relatively poor, with a significant performance degradation under typical environmental conditions. The present study has shown that the organic cations in the organic-inorganic halide perovskites have a significant effect on the environmental, electrical, light, and temperature stability of these TFT devices. The effects of different organic spacer cations (butylammonium (BA+), octylammonium (OA+), phenylethylammonium (PEA+), and 2-fluorophenylethylammonium (FPEA+) cations) on the environmental, electrical, light, and temperature stability of the TFT devices have here been investigated. We observed that an extension of the organic cation chain length, in addition to an incorporation of a benzene ring in the cation, will contribute to a comprehensive enhancement of the stability of the TFT devices. However, the incorporation of a benzene ring in the organic cation chain resulted in a more pronounced effect on this stability, as compared with the chain length extension.