Laser-induced microstructuring of two-dimensional layered inorganic–organic perovskites

Abstract

Non-contact bi-directional micropatterning of two-dimensional (2D) layered inorganic–organic (IO) perovskite [(R-NH₃)₂PbI₄, R = organic moiety] thin films by direct laser writing (DLW) has been reported. These 2D materials are in the form of natural multiple quantum well (MQW) structures and show excitonic luminescence at room temperature because of quantum and dielectric confinement effects. Systematic optical and structural analyses of these laser processed hybrid systems provide an insight into laser–matter interaction and a pathway to develop technology to define complex 2D material based devices with new functionalities. These laser–matter interaction studies reveal several concurrent processes: single photon absorption, material ablation, melting and agglomeration of nanostructures and chemical/physical modifications. This study also provides an insight into chemical and optical changes in laser processed 2D perovskites which subsequently can be recovered by chemical processing. Apart from controllable feature sizes, the prolonged laser exposure results in material agglomeration in the form of nano-pillars at the laser track boundaries. Low-cost micro/nano-scaffolding of IO perovskites may have several important advantages in scalable optoelectronic devices, the realisation of luminescent photonic architectures (photonic crystals and waveguides), and light harvesting elements for IO LEDs and solar cells.