A Universal Perovskite Nanocrystal Ink for High-Performance Optoelectronic Devices

Semiconducting lead halide perovskite nanocrystals (PNCs) are regarded as promising candidates for next-generation optoelectronic devices due to their solution processability and outstanding optoelectronic properties. While the field of light-emitting diodes (LEDs) and photovoltaics (PVs), two prime examples of optoelectronic devices, has recently seen a multitude of efforts toward high-performance PNC-based devices, realizing both devices with high efficiencies and stabilities through a single PNC processing strategy has remained a challenge. In this work, diphenylpropylammonium (DPAI) surface ligands, found through a judicious ab-initio-based ligand search, are shown to provide a solution to this problem. The universal PNC ink with DPAI ligands presented here, prepared through a solution-phase ligand-exchange process, simultaneously allows single-step processed LED and PV devices with peak electroluminescence external quantum efficiency of 17.00% and power conversion efficiency of 14.92% (stabilized output 14.00%), respectively. It is revealed that a careful design of the aromatic rings such as in DPAI is the decisive factor in bestowing such high performances, ease of solution processing, and improved phase stability up to 120 days. This work illustrates the power of ligand design in producing PNC ink formulations for high-throughput production of optoelectronic devices; it also paves a path for dual-mode devices with both PV and LED functionalities.

Automated summary

This study explores a method to achieve high efficiency and stability in semiconducting lead halide perovskite nanocrystals (PNCs) through a single processing strategy by finding suitable surface ligands. The PNC ink prepared using this method can be used to fabricate both LED and PV devices, with peak electroluminescence external quantum efficiency of 17.00% and power conversion efficiency of 14.92%. It is found that a careful design of the aromatic rings in the ligands is crucial for achieving high performance, ease of processing, and improved phase stability. This research demonstrates the role of ligand design in PNC ink formulations for high-throughput production of optoelectronic devices and paves the way for dual-mode devices with both PV and LED functionalities.