Supercooled liquid phases of luminescent zero dimensional metal halide hybrids

Abstract

Chemical design of metal halide hybrids (MHHs) with suppressed melting point (Tm) allows access to glassy phases from their liquid-melts. Thermal phase change (crystal-melt-glass) properties of glassy MHHs (with glass transition temperature Tg greater than room temperature) have been exploited for device applications. However, room temperature stable supercooled liquid (SCL) MHHs (with Tg less than room temperature), originating from glass-SCL phase change, remain inaccessible. Here, a molecular design strategy is reported to access ambient stable, melt-processable, SCL multimetallic bromide hybrids (Mn sup(2+),Cd sup(2+); Mn sup(2+),Zn sup(2+); Benzyltributylammonium) with low T sub(g) (15-16 degrees C), low T sub(m) (90-100 degrees C), green luminescence, and high optical transparency. Structural, optical, thermal, and computational analyses highlight chemical design principles and support dopant (Mn sup(2+)) based luminescence. Rheological measurements confirm the SCL phase that shows thermal hysteresis and estimate relaxation time scales. This work provides a new material platform showcasing enhanced melt-processability for fabrication of moldable devices, unravelling chemical makeup-property correlation and expanding the material phase types of MHHs.