Stable PeLEDs · Towards Stable Perovskite Light-Emitting Diodes
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2019-09-01 → 2020-08-31
- EU contribution
- €112,467
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Towards Stable Perovskite Light-Emitting Diodes
Recent years, perovskite light-emitting diodes (LEDs) have achieved great progress, with external quantum efficiency (EQE) exceeding 20%. However, the poor stability becomes obstacle to the practical application of perovskite LEDs. The degradation of perovskite LEDs working under electrical stress can be caused by Auger recombination, ion migration, Joule heating or deterioration of perovskite material, etc. This project aims to demonstrate fundamental degradation mechanism of perovskite LEDs under electrical stress. Then high-performance perovskite LEDs can be fabricated. This project demonstrates that the ion migration under electrical stress is the main reason for degradation in three-dimensional (3D) FAPbI3 perovskite LEDs. By introducing bifunctional-molecule 3-chlorobenzylamine (3Cl-BA) additive into the perovskite precursor solution to suppress the detrimental ion migration, bright near-infrared perovskite LEDs with a peak EQE of 16.6% were achieved, which exhibits a record half-lifetime of 49 h at room temperature under a constant current density of 100 mA cm-2. Furthermore, this project reveals that the already existed heterogeneous distribution of halides in the as-deposited perovskite films is the main reason for the halide phase separation during operation of LED device. By simply introducing zwitterionic surfactants to improve the homogeneity of the halides in the precursor solution, we can overcome the phase segregation issue and obtain spectrally-stable single-phase blue-emitting perovskites. This project not only increases the knows on how to design stable perovskite LEDs, but also makes significant contribution to the development of perovskite LEDs. It suggests a design strategy of additive to achieve high-quality perovskites, which is also important for perovskite solar cell community, where the ion migration and phase segregation need to be minimized to suppress the hysteresis and enhance device stability.
Data: CORDIS, © European Union
Project objective
The organometal halide perovskites as optoelectronic materials possess numerous advantages of high photoluminescence quantum efficiencies, low cost, low-temperature and large-area solution process, exhibiting great potential in display and lighting applications. Considerable progress has been made in efficiency of perovskite light-emitting diode (PeLED), but the stability issues limit its commercialization. The goal of this project is to achieve stable and efficient PeLEDs based on addressing the root causes of the degradation of device under current stress, which may be related to Auger recombination, ion migration and Joule heating. The plan is to incorporate many of the technologies first developed in the host group at the Cavendish Laboratory and my group at the Nanjing Tech University, which have been global leaders in PeLEDs development over the last few years. This project will evaluate the lifetime of PeLEDs under varying current densities and temperatures. Microscopic post-mortem examination and photophysics characterization of aged devices will be used to determine failure mechanisms. The fundamental physics-based models of degradation will be developed. Finally, the project will achieve high efficiency and long operational lifetime PeLEDs by optimization of materials, deposition process and device structure. This project involves multiple disciplines and complementary expertise. The training will broaden my knowledge on photophysics, device physics and strengthen my transferable skills. Further, it will allow the transfer of my knowledge to the host group and develop a lasting collaboration. It is expected that the implementation of this project will promote the commercialization of PeLEDs, and have long lasting benefits both for fundamental research and industry in Europe.
Original text from CORDIS.
Participants
- THE CHANCELLOR MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE · CAMBRIDGECoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union