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Zigzag edged nanographenes such as peri‐acenoacenes are promising materials for organic lasers, but the effects of heteroatom doping on the electronic properties and gain medium performance remain unclear. Herein, the facile synthesis of a new 1,2‐oxaborine (BO) doped peri‐tetracenotetracene derivative, the bis(1,2‐oxaborine)peri‐tetracenotetracene (BOTT‐Mes), is reported. X‐ray crystallographic analysis confirms the BO‐doped planar structure and the nonexistence of intermolecular π–π stacking in solid state. Compared with the all‐carbon peri‐tetracenotetracene derivative (TT‐Ar), the BO‐doped BOTT‐Mes exhibits more disrupted π‐conjugation at the BO sites, a lower‐lying highest occupied molecular orbital, and a larger energy gap. Due to its rigid skeleton and nonaggregative feature, it displays well‐resolved absorption and emission spectra with a small Stokes shift (8 nm) and high photoluminescence quantum yield (80%) when it is dispersed in a polystyrene (PS) thin film. Notably, 1,2‐oxaborine doping improves the film amplified spontaneous emission (ASE) performance, with a lower ASE threshold (Eth‐ASE = 66 µJ cm–2) as compared to the TT‐Ar doped PS film (Eth‐ASE = 100 µJ cm–2). Furthermore, a low threshold (22 µJ cm–2) solution‐processed distributed feedback laser is fabricated, indicating the feasibility of using BOTT‐Mes as gain medium for practical laser applications. [ABSTRACT FROM AUTHOR]

Chemically synthesized zigzag-edged nanographenes (NG) have recently demonstrated great success as the active laser units in solution-processed organic distributed feedback (DFB) lasers. Here, we report the first observation of dual amplified spontaneous emission (ASE) from a large-size NG derivative (with 12 benzenoid rings) dispersed in a polystyrene film. ASE is observed simultaneously at the 685 and 739 nm wavelengths, which correspond to different transitions of the photoluminescence spectrum. Ultrafast pump-probe spectroscopy has been used to ascertain the underlying photophysical processes taking place in the films. DFB lasers, based on these materials and top-layer nanostructured polymeric resonators (i.e., one or two-dimensional surface relief gratings), have been fabricated and characterized. Lasers emitting close to either one of the two possible ASE wavelengths, or simultaneously at both of them, have been prepared by proper selection of the resonator parameters. [ABSTRACT FROM AUTHOR]