Lamellar Organic Light-Emitting Crystals Exhibiting Spectral Gain and 3.6% External Quantum Efficiency in Transistors

We report an organic lamellar single crystal as a versatile optoelectronic material in optical pumping and light-emitting transistors. The styrene derivative crystals with intrinsically ordered stacking structures, low impurities, and high photoluminescence efficiency offer a low threshold energy of 21 μJ cm–2 for amplified spontaneous emission and extraordinary device performance in terms of a striking external quantum efficiency of 3.63%, far exceeding the benchmark value in this field.