HAlogen bonding for Lead-free LOW-dimensional Perovskite Light Emitting Diodes

Lighting sector accounts for nearly ~ 20 % of the global electricity consumption, over 2 % of green-house emission and carbon footprint. With the growing demand of energy consumption, it is urgent to develop alternative technologies, that mitigate global warming. In this regard, light emitting diodes (LEDs) have revolutionized lighting technology, as they are recyclable, energy-efficient and require less power than traditional bulbs. In this regard, LEDs has been lighting our homes, industries ad even medical applications. Particularly, Organic-LEDs (OLEDs) containing organic/polymer molecules such as anthracenes, coumarin derivatives, biphenyl acetylene aryl derivatives etc have been successfully employed in our smartphones and screens. However, their application is limited by cost of manufacture and difficulty in color-tuning with high color-purity, especially over the visible and infra-red regions. Since 2009, a new class of semiconductors known as halide perovskites have emerged as potential candidates for next-generation LEDs owing to their feasibility in terms of processing and manufacturing and excellent opto-electronic properties. However, they possess lead toxicity and are unstable under ambient conditions. In this regard, replacement of lead with other alternatives and use of functional spacer cation has been adopted as a strategy to overcome these challenges. Specifically, designing a functional cation with halogen bond (XB) is rarely studied and can be useful in developing novel halide perovskites with improved structural stability (>1 year, ambient conditions) and improving luminescence properties for PeLEDs. Thus, with the help of MSCA-PF funding program, HALLOW-PeLEDs, attempts to combine the synergy of physical chemistry with supramolecular interactions for optoelectronic applications, by harnessing the virtues of halogen bonds (XB) to form ordered low-dimensional lead-free metal halide perovskites for obtaining efficient Perovskite LEDs (PeLEDs).