Researchers from Taiyuan University of Technology, University of Electronic Science and Technology of China, Southwest Jiaotong University and Shimmer Center have explained that unbalanced carrier injection and internal defects within the perovskite pose significant challenges to the performance of perovskite optoelectronic devices. To address this issue, they developed a strategy of functional molecule surface infiltration treatment.
In the new treatment, a 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) acetone solution is used to treat the perovskite film. Such treatment facilitates the reconstruction of the perovskite film’s surface and promotes the infiltration of TPBi into the grain boundaries, thereby reducing defects and effectively enhancing electron injection between the emitting layer and the transport layer.
The resulting all-inorganic Pero-LEDs showed greatly improved external quantum efficiency to 14.74 % and an ultra-high luminescence up to 301,831 cd m−2.
The device’s T50 lifetime reached 985 s (@7,592 cd m−2), which is 3.4 times that of the control.
The work highlights that constructing heterointerface coulomb interfaces to passivate surface/bulk defects and synergistically improving carrier injection balance can be an effective strategy to improve all-inorganic Pero-LEDs’ efficiency and operational stability.
