High-Performance Organic Laser Semiconductor Enabling Efficient Light-Emitting Transistors and Low-Threshold...

Area of Science:

• Materials Science
• Organic Electronics
• Photonics

Background:

• Organic light-emitting transistors (OLETs) are promising for electrically pumped organic solid-state lasers.
• Key challenges include finding organic semiconductors with high solid-state emission efficiency, balanced ambipolar mobility, and large stimulated emission cross-sections.

Purpose of the Study:

• To design and synthesize a novel organic semiconductor for OLETs.
• To achieve efficient electrically pumped organic solid-state lasers.

Main Methods:

• Designed and synthesized the 4,4'-bis(2-dibenzothiophenyl-vinyl)-biphenyl (DBTVB) molecule.
• Prepared ultrathin single-crystal microplates of DBTVB with herringbone packing.
• Investigated charge transport, emission efficiency, and laser characteristics through theoretical and experimental methods.

Main Results:

• DBTVB crystals exhibited balanced mobilities (μh = 3.55 ± 0.5, μe = 2.37 ± 0.5 cm2 V−1 s−1) and high solid-state emission efficiency (Φs = 85 ± 3%).
• Achieved low-threshold laser characteristics with an internal quantum efficiency near 100%.
• Record-high electroluminescence external quantum efficiency of 4.03% was demonstrated.

Conclusions:

• DBTVB is a highly efficient organic semiconductor for OLETs.
• The material's properties facilitate efficient charge transport and highly emissive H-aggregates, enabling laser emission.
• This work advances the development of electrically pumped organic solid-state lasers.