Matched Electron-Transport Materials Enabling Efficient and Stable Perovskite Quantum-Dot-Based Light-Emitting Diodes.
Angew Chem Int Ed Engl
; 63(42): e202410689, 2024 Oct 14.
Article
in En
| MEDLINE
| ID: mdl-39072910
ABSTRACT
Light-emitting diodes (LEDs) based on perovskite quantum dots (QDs), abbreviated as P-QLEDs have been regarded as significantly crucial emitters for lighting and displays. Efficient and stable P-QLEDs still lack ideal electron transport materials (ETM), which could efficiently block hole, transport electron, reduce interface non-radiative recombination and possess high thermal stability. Here, we report 2,4,6-Tris(3'-(pyridine-3-yl) biphenyl-3-yl)-1,3,5-triazine (TmPPPyTz, 3P) with strong electron-withdrawing moieties of pyridine and triazine to modulate the performance of P-QLEDs. Compared with commonly used 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), the pyridine in 3P have a strong interaction with perovskites, which can effectively suppress the interface non-radiative recombination caused by the Pb2+ defects on the surface of QDs. In addition, 3P have deep highest occupied molecular orbital (HOMO) (enhancing hole-blocking properties), matched lowest unoccupied molecular orbital (LUMO) and excellent electron mobility (enhancing electron transport properties), realizing the carrier balance and maximizing the exciton recombination. Furthermore, high thermal resistance of 3P obviously improves the stability of QDs under variable temperature, continuous UV illumination, and electric field excitation. Resultantly, the P-QLEDs using the 3P as ETM achieved an outstanding performance with a champion EQE of 30.2 % and an operational lifetime T50 of 3220â
hours at an initial luminance of 100â
cd m-2, which is 151 % and about 11-fold improvement compared to control devices (EQE=20 %, T50=297â
hours), respectively. These results provide a new concept for constructing the efficient and stable P-QLEDs from the perspective of selective ETM.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Angew Chem Int Ed Engl
Year:
2024
Document type:
Article
Affiliation country:
China
Country of publication:
Germany