Large-area inorganic perovskite quantum dot microdisk microlasers enabled by orthogonal photolithography*

Solution-processed all inorganic perovskite quantum dots have attracted great attention due to their facile synthesis and promising optical properties such as high quantum yield, high net optical gain and high absorption cross section. However, the ionic nature of these quantum dots makes them prone to dissolution in common polar solvents, which severely hinder the integration of these QDs into patterned photonic structures using standard lithography processes. Here, we report a novel lithography based patterning approach that incorporates fluorinated polymer resist which provides orthogonality to both polar and non-polar materials, thus enabling the facile fabrication of large-area photonic structures including microdisk laser arrays and multicolor pixels. Optical characterization of these structures includes measuring net optical gain value, lasing threshold and mode activity. Importantly, this novel patterning approach can be universally applied to various type of nanocrystals and act as a significant step to the future development of quantum dot based optoelectronic devices that require high-resolution large-area patterned structures.