Small amines bring big benefits to perovskite-based solar cells and light-emitting diodes

Small amines featuring the combination of amino groups and other organic moieties have emerged as some of the most promising additives or surface ligands candidates for improving the performances of perovskite solar cells (PSCs) and perovskite-based light emitting diodes (Pe-LEDs). The amine molecules show great potential to have multifunctionalities and salient advantages via rational tailoring of their molecular structures. This leads to the question of how a small amount of amine molecules incorporated in perovskite films can bring big benefits to the perovskite-based optoelectronic devices. To answer, in this review, we unlock the secrets of remarkable performance enhancement of PSCs and Pe-LEDs with amine modification, aiming to establish a structure-property performance relationship. In addition, feasible rules to design amines with ideal molecular structures are critically discussed. Finally, insights are given for future research trends and the rational design of functional amine molecules for more efficient and stable perovskite-based optoelectronic devices.