PSC and LED Quantum Efficiency Measurement Tool: Practical Application of LQ-100X! How to optimize Q-2D perovskite LED performance?
In August 2021, Advanced Materials (Impact Factor 30.849) published a study. Metal halide perovskites are suitable materials for light-emitting application because of their high defect tolerance of defects, high color purity (narrow fullwidth at half-maximum of emission peak), tunable band gap and solution processability. Compared with typical 3D perovskite, Quasi-2D (Q-2D) perovskite has higher exciton binding energy and more effective radiation recombination and exhibits excellent luminescence properties. However, Quasi-2D (Q-2D) perovskite feature a multiphase structure with abundant grain boundaries and interfaces, it will cause nonradiative loss during the energy-transfer process. By manipulating the crystallization kinetics of different n-phases to make energy transfer in Quasi-2D (Q-2D) perovskites more efficient. The researchers used a series of alkali-metal bromides to manipulate the nucleation and growth of Q-2D perovskites, which may be related to the Coulomb interaction between alkali-metal ions and the negatively charged PbBr64- frames.
Impact of Li+, Na+, K+ on the nucleation and growth of Q-2D perovskites.
Enlitech’s Absolute Electroluminescence EQE/ Photoluminescence Quantum Yield Tester (LQE-100-EL, now LQ-100X) was used in this study to help to measure J-V-L curve, EQE and operational stability measurement of our perovskite light-emitting diodes (LEDs) and the PLQY measurement. It was found that the addition of KBr would restrict the nucleation of the high-n phases and allow the subsequent growth of the low-n phases. The synergistic manipulation of nucleation and growth contributes to a more homogeneous n-phases distribution and promoted energy transfer, along with a more ordered crystal structure. The optimized PEA2FA2Pb3Br10 film has a photoluminescence quantum yield (PLQY) of 66.8%. In addition, highly efficient green Q-2D perovskites LEDs achieve a the maximum EQE of 18.15% and he highest luminance of 25 800 cd m-2. It further confirmed a new method to optimize the performance of Q-2D perovskite LEDs and emphasized the importance of manipulating crystallization kinetics.
In this research, Enlitech’s LQ-100X can not only assist in the measurement of PLQY, LED and other characteristics, but also can be applied to the quantum efficiency measurement of perovskite solar cell (PSC). It is a good helper to assist you in experiments and application projects!
Performance of LED devices of Q-2D perovskite.(d) J–V–L–EQE curves of the champion device with 0.5KBr added.(e) Histogram of maximum EQE measured from 50 devices with 0.5KBr added.(f) Stability of the perovskite LED measured at a constant current density of 0.25 mA cm–2, with an initial luminance around 140 cd m–2.
As show in the TA measurement in Figure. , Li/Na-added films exhibit slower energy transfer and severe energy loss, which accounts for the lower PLQY.
Recommended Instruments: LQ-100X Absolute Electroluminescence EQE/ Photoluminescence Quantum Yield Tester
Keywords: Quasi-2D perovskite, LED, crystallization kinetics, Quantum Efficiency