Preferential vertically oriented nanopillar perovskite induced by poly(9-vinylcarbazole) field-effect transistor

Abstract Organic-inorganic hybrid perovskite could potentially be used to create field-effect transistors (FETs) with high field-effect mobility. However, the energy level mismatch at the deep valence band maximum perovskite-contact junction and morphological defects greatly limit the charge transport in the thin film. In this work, we demonstrated charge injection can be improved by introducing Nafion as a surface modifier on top of the Indium tin oxide. Incorporating poly (9-vinylcarbazole) PVK into a quasi-one-dimensional precursor solution induced preferential vertically orientated nanopillars as revealed by synchrotron-based two-dimensional grazing incident X-ray diffraction. This simultaneously reduced the grain boundaries and improved pin-hole free films. As a result, maximum hole mobility of 0.012 cm2/Vs was achieved with a reduction in the hysteresis. Our work demonstrated the dependence of FETs performance on the injection barrier and perovskite nanopillar microstructure.