Perovskite materials have gathered significant attention due to their remarkable optoelectronic properties and potential applications in various fields. Some synthetic methods offer control over the size and shape of perovskite nanostructures [1], facilitating a comprehensive exploration of their optical properties.

This study explores the synthesis and characterization of perovskite materials with a particular emphasis on diverse dimensionalities, especially nanowires. The one-dimensional nature of perovskite nanowires can provide excellent electrical, optical, and physical properties, such as improved light trapping, lower defect density, longer photocarrier lifetime and better mechanical properties [2]. As such, they have been used for solar cells, photodetectors and LEDs, among others [3]. The key question then is understanding how excitation travels through the material and whether this behavior differs from that in the bulk material solely due to the shape.

Using Transient Photoluminescence microscopy,[4] we can directly visualize the spatial movement of energy carriers with sub-nanosecond and few-nanometer resolution in CsPbBr₃ nanowires grown by hot-injection synthesis . Our results reveal efficient transport of energy carriers with high anisotropy imposed by the dimensionality of the structure. Power dependent spectroscopy moreover reveals that energy transport is dominated by free charges.

To further study the influence of morphology on the optoelectronic properties of perovskite nanowires, we use scanning-probe of an atomic force microscope (AFM) to manipulate the nanowires and create complex nanostructures [5]. For efficient manipulation with AFM, we have developed different methods to fine-tune the substrate interaction, including the use of self-assembled monolayers and optimization of the wire surface using oleic acid saturation. We will discuss how mechanically induced strain can influence the transport properties of the nanowires, correlating these effects with high resolution TEM imaging.  

These studies provide crucial insights into the dynamic behavior of energy carriers within these materials and their relationship with the local morphology. The findings from this study not only deepen our understanding of perovskite nanomaterials but also pave the way for their use in advanced optoelectronic devices and applications.