Antisolvent Choice Determines the Domain Distribution of Quasi-2D Perovskite for Blue- Emitting Perovskites-Based Light Emitting Devices

摘要

Antisolvent treatment is paramount in the fabrication of high-efficiencyperovskite optoelectronic devices as it affords a high crystallization ratecritical for the formation of pin holes-free perovskite films. Although theantisolvent choice determines the domain distribution of quasi-2D perovskite,and hence the emission wavelength (blue vs green), as well as itslight emission efficiency, few studies have examined it in detail. Herein,the crystallization dynamics and resulting optoelectronic properties of PBA(phenyl-butyl-ammonium)-based quasi-2D perovskites (A′_2A_(m-1)Pb_mX_(3m+1)),which are commonly employed to create blue emissive films, are scrutinizedfor the first time through in situ photoluminescence measurementsduring film formation. The m domain distribution can be tailored byselecting antisolvents with various solubilities of PBA cation. Antisolventswith higher PBA solubility promote the formation of smaller bandgap filmsdue to larger m domains and vice versa. This study effectively reveals aroute to tailor quasi-2D perovskite optoelectronic properties via antisolventengineering. Fine-tuning the optoelectronic properties can be done byblending two antisolvents with contrasting PBA cations solubility. By doingso, a blue emissive light emitting diode with emission wavelength rangingfrom 471 to 509 nm can be fabricated with an external quantum efficiencyof 2.9% at 471 nm.