TY  - JOUR
A1  - Chen, Xing
A1  - Meng, Guoyun
A1  - Liao, Guanming
A1  - Rauch, Florian
A1  - He, Jiang
A1  - Friedrich, Alexandra
A1  - Marder, Todd B.
A1  - Wang, Nan
A1  - Chen, Pangkuan
A1  - Wang, Suning
A1  - Yin, Xiaodong
T1  - Highly Emissive 9-Borafluorene Derivatives: Synthesis, Photophysical Properties and Device Fabrication
JF  - Chemistry—A European Journal
N2  - A series of 9-borafluorene derivatives, functionalised with electron-donating groups, have been prepared. Some of these 9-borafluorene compounds exhibit strong yellowish emission in solution and in the solid state with relatively high quantum yields (up to 73.6 % for FMesB-Cz as a neat film). The results suggest that the highly twisted donor groups suppress charge transfer, but the intrinsic photophysical properties of the 9-borafluorene systems remain. The new compounds showed enhanced stability towards the atmosphere, and exhibited excellent thermal stability, revealing their potential for application in materials science. Organic light-emitting diode (OLED) devices were fabricated with two of the highly emissive compounds, and they exhibited strong yellow-greenish electroluminescence, with a maximum luminance intensity of >22 000 cd m\(^{-2}\). These are the first two examples of 9-borafluorene derivatives being used as light-emitting materials in OLED devices, and they have enabled us to achieve a balance between maintaining their intrinsic properties while improving their stability.
KW  - boron heterocycles
KW  - photophysics
KW  - organic light-emitting diodes
KW  - luminescence
KW  - density functional calculations
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256738
VL  - 27
IS  - 20
ER  - 
TY  - JOUR
A1  - Wu, Zhu
A1  - Nitsch, Jörn
A1  - Marder, Todd B.
T1  - Persistent room-temperature phosphorence from purely organic molecules and multi-component systems
JF  - Advanced Optical Materials
N2  - Recently, luminophores showing efficient room-temperature phosphorescence (RTP) have gained tremendous interest due to their numerous applications. However, most phosphors are derived from transition metal complexes because of their intrinsic fast intersystem crossing (ISC) induced by strong spin–orbit coupling (SOC) constants of the heavy metal. 

Metal-free RTP materials are rare and have become a promising field because they are inexpensive and environmentally friendly. This review summarizes organic molecular materials with long triplet lifetimes at room temperature from the perspective of whether they stem from a molecular or multi-component system. Among purely organic phosphors, heteroatoms are usually introduced into the backbone in order to boost the singlet–triplet ISC rate constant. 

In multi-component systems, useful strategies such as host–guest, polymer matrix, copolymerization, and supramolecular assembly provide a rigid matrix to restrict nonradiative pathways thus realizing ultralong RTP.
KW  - inorganic chemistry
KW  - non-radiative  decay
KW  - polymer matrix
KW  - intersystem  crossing
KW  - luminescence
KW  - photophysics
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256415
VL  - 9
IS  - 20
ER  -