2020/01/16 by A. N. Mishra, Masoud Alahbakhshi, Mishra, Aditya +11
Engineering · Materials Science · #Applied Physics (physics.app-ph) #Chemical Physics (physics.chem-ph) #Conducting polymers and applications #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Optics (physics.optics) #Organic Light-Emitting Diodes Research #Perovskite Materials and Applications
paper · pdf · doi:10.48550/arxiv.2001.05950
openalex publication_date 2020/01/16 · openalex created_date 2022/07/26 · openalex updated_date 2026/07/28
Hybrid perovskites are emerging as highly efficient materials for\noptoelectronic applications, however, the operational lifetime has remained a\nlimiting factor for the continued progress of perovskite light emitting devices\nsuch as light emitting diodes (LEDs) and perovskite light emitting\nelectrochemical cells (PeLECs). In this work, PeLECs utilizing an optimized\nfraction of LiPF6 salt additive exhibit enhanced stability. At 0.5 wt% LiPF6,\ndevices exhibit 100 h operation at high brightness in excess of 800 cd/m2 under\nconstant current driving, achieving a maximum luminance of 3260 cd/m2 and power\nefficiency of 9.1 Lm/W. This performance extrapolates to a 6700 h luminance\nhalf-life from 100 cd/m2, a 5.6-fold improvement over devices with no lithium\nsalt additive. Analysis under constant voltage driving reveals three current\nregimes, with lithium addition strongly enhancing current in the second and\nthird regimes. The third regime correlates degradation of luminance with\ndecreased current. These losses are mitigated by LiPF6 addition, an effect\npostulated to arise from preservation of perovskite structure. To further\nunderstand lithium salt addition, electrochemical impedance spectroscopy with\nequivalent circuit modeling is performed. Electrical double layer widths from\nionic redistribution are minimized at 0.5wt% LiPF6 and inversely correlate with\nefficient performance.\n