Nano-Lithography of Metal-Halide Perovskites for the Realization of Distributed Feedback Lasers

Metal-halide perovskites are soluble semiconductors which have emerged in recent years as a powerful material system in the field of photonics. Due to their promising electronic and optical properties, tremendous progress has been made in the performance of perovskites solar cells, light emitting diodes, lasers and more. However, due to their instable nature, the ability to pattern these materials, especially in the nano-regime is extremely challenging. In this work, we demonstrate the realization of active optical devices using two different approaches. First, we realize distributed feedback lasers using direct nano-imprint lithography (NIL). These lasers exhibit low thresholds and single mode operation.

While direct NIL can define nano elements by molding the material, it is incapable of removing desired geometries from specific areas. Thus, a full lithography technique capable of defining nanometer scale elements in perovskite materials is sought for. The second approach we demonstrate is a complete lithographic scheme for thin perovskite films. The process is simple, fast, scalable, and exhibits sub-micron resolution. This is the first demonstration of complete, high-resolution, lithography of perovskites films exhibiting the smallest perovskite features realized using a top-down lithography technique.

We use the second approach combined with direct NIL to generate geometrically defined DFB lasers. On-chip integrated lasers are key components in photonic circuits. The ability to control the geometry and position of the device in the photonic chip and to couple the light to other components are crucial tools for the designer. Our approach offers a powerful and versatile tool for the realization of various active components, rendering it an important step towards integrated perovskite photonics. Moreover, the approach can be easily extended to different fields of perovskite research such as photovoltaics, meta-surfaces, transistors and more.