Silicon-based perovskite light-emitting diodes (Si-based PeLEDs) have great potential in specific optoelectronic application scenarios due to the combination of the excellent light-emitting characteristics of perovskite
and the maturity of silicon technology. In addition, the good thermal conductivity of the silicon substrate will effectively dissipate the Joule heat generated by the device during operation, thereby significantly improving the device performance of PeLEDs under large injection conditions. However, it is still challenging to realize highly efficient Si-based PeLEDs. Recently, Fang Yanjun, a researcher in the team of Academician Yang Deren of Zhejiang University, reported a high-performance silicon-based perovskite light-emitting diode device.
By constructing the microcavity effect and the MACl-mediated perovskite phase management strategy, external quantum efficiency (EQE) greater than 20% is generally achieved near 760 nm. The dosage of 0.5 mg/mL of MACl can obtain the EQE of 20.1% and the radiance of 155.9 mW cm-2 at the same time, and the dosage of 1.5 mg/mL can obtain the EQE of 20.3%. This is the most efficient top-emitting PeLEDs and Si-based PeLEDs known so far.
The study found that by precisely controlling the thickness of each functional layer in the device, Si-based PeLEDs can meet the resonance conditions of the microcavity, thereby having an ultra-high light extraction rate in a specific wavelength range. Adding MACl to the perovskite precursor solution can promote the transformation of the perovskite phase from the original quasi-nanocrystalline structure to the quasi-two-dimensional structure. The improvement of PLQY, the improvement of PL lifetime, and the reduction of defect density brought about by this transformation process are important reasons for obtaining high-performance Si-based PeLEDs.
Yan Minxing et al. Tailoring the 2D/3D Phase Segregation for Highly Efficient Si-Based Perovskite Light-Emitting Diodes. ACS Materials Letters (2022)
DOI: 10.1021/acsmaterialslett.2c00656
source:https://pubs.acs.org/doi/10.1021/acsmaterialslett.2c00656