Abstract

Hybrid organic-inorganic antimony halides have attracted increasing attention due to the non-toxicity, stability, and high photoluminescence quantum yield (PLQY). To shed light on the structural factors that contribute to the high PLQY, five pairs of antimony halides with general formula A₂SbCl₅ and A₂Sb₂Cl₈ are synthesized via two distinct methods and characterized. The A₂SbCl₅ type adopts square pyramidal [SbCl₅] geometry with near-unity PLQY, while the A₂SbCl₈ adopts seesaw dimmer [Sb₂Cl₈] geometry with PLQY~0%. Through combined data analysis with the literature, we have found that A₂SbCl₈ series with square pyramidal geometry generally has much longer Sb…Sb distances, leading to more expressed lone pairs of Sb (III). Additional factors including Sb-Cl distance and stability of antimony chlorides may also affect PLQY. Our targeted synthesis and correlated insights provide efficient tools to precisely form highly emissive materials for optoelectronic applications.