Tailored CsPbX3 Nanorods for Electron-Emission Nanodevices

Abstract

Going beyond much cultivated photovoltaic aspects of all inorganic lead halide perovskite, here we explored electron field emission of CsPbX3 nanorods, where X represents different halides, specifically Cl, Br, and I. Starting with room-temperature preparation of different perovskite nanorods, we examined their electron-emission behavior and found CsPbI3 as best electron emitter among the synthesized samples, which showed that low work function and high aspect ratio drove the best emission performance. Aspect ratios of the CsPbI3 nanorods were tailored via alteration of processing temperature. Nanorods prepared at 90 °C possessing maximum aspect ratio delivered a current density of 133 μA/cm2 at 8 V/μm applied external field. With an expectation of gaining better emission performance from as-synthesized optimized nanorods, reduced graphene oxide (rGO) was further attached to them. Relying on the emission beneficial electronic features of rGO as-prepared CsPbI3-rGO composite delivered significantly improved electron emission performance with low turn-on field and high field enhancement value, which are much better than the individual structural blocks. Easy electron passage from the composite as a consequence of work function decrement as well as high field amplification at graphene basal plane supported by one-dimensional CsPbI3 nanorod renders improvement in field values. Experimentally observed electron emission result is further verified through electrostatic field distribution calculation using ANSYS software. Such results indicated the potential utility of these kinds of perovskite materials in field electron-emission nanodevices.