Excited states engineering enables efficient near-infrared lasing in nanographenes

Abstract

The spectral overlap between stimulated emission (SE) and absorption from dark states (i.e. charges and triplets) especially in the near-infrared (NIR), represents one of the most effective gain loss channel...

Peri‐Acenoacene for Solution Processed Distributed Feedback Laser: The Effect of 1,2‐Oxaborine Doping

“…[ 18 ] Both NGs present similar performances in terms of gain and losses (Figure S5, Supporting Information, and Table 1), with losses being mainly dominated by those of the PS matrix. Moreover, the ASE threshold and gain values of BOTT‐Mes are comparable to those obtained for other NGs [ 5,19 ] and only slightly inferior in performance than those of state of the art organic molecules dispersed in inert matrixes, such as perylenediimides [ 20 ] and carbon‐bridged oligo( p ‐phenylenevinylene)s. [ 21 ] Additionally, the ASE photostability was tested under an uninterrupted ns‐pulsed pump (10 Hz) at four to five times E th‐ASE in ambient conditions. The ASE half‐life parameter (τ 1/2 ) is determined as the number of pulses needed for the initial output intensity to reach half its initial value (Figure S6, Supporting Information).…”

“…The fabricated device presents similar laser properties to that previously reported for DFB laser based on TT‐Ar ( E th‐DFB = 25 ± 3 µJ cm –2 for TE 0 ) and other NGs such as FZ1 (50 ± 5 µJ cm –2 for TE 0 ), FZ2 (11 ± 1 µJ cm –2 for TE 0 ) or DBOV‐FAI (50 ± 5 µJ cm –2 for TE 0 ). [ 5,19b ] Additionally, the device based on BOTT‐Mes shows a threshold value similar to those found for state‐of‐the‐art organic compounds dispersed in inert matrixes, e.g., PDI‐O (22 ± 2 µJ cm –2 ) or COPV‐6 (7 ± 1 µJ cm –2 ). [ 29 ]…”

“…Despite the undesired effect of the BO heteroatoms over the photostability, this is still in the same order of magnitude as that found for similar active materials consisting of NGs dispersed in PS matrices. [ 5,19 ] The broken conjugation resulting from doping the NG scaffold with BO heteroatoms at the zigzag edges mainly blueshifts the ASE band, whilst preserves or even improves the amplification properties and hardly reduces the compound photostability. Therefore, BO units are promising substitution groups to simultaneously regulate the electronic structure and preserve optimal gain properties in the system of BOTT and TT‐Ar .…”

Small Size, Big Impact: Recent Progress in Bottom‐Up Synthesized Nanographenes for Optoelectronic and Energy Applications

“…The fascinating combination of strong and tunable fluorescence [ 72 , 91 , 96 , 97 ] with high chemical and environmental stabilities [ 30 ] makes GQDs also suitable for optical imaging applications. [ 76 ] Moreover, compared to broad PL spectra due to a wide size distribution of NGs produced by top‐down synthesis, [ 77 , 98 , 99 ] atomically‐precise structures of bottom‐up synthesized GQDs with monodispersed sizes enable extremely narrow PL spectra.…”

Real‐Time Tunable Red/Near‐Infrared Solid‐State Emitters in the First Biological Window: 9,9‐Diethyl‐2‐diphenylaminofluorene‐Based Push‐Pull Fluorophores for Distributed Feedback and Random Lasing Applications

“…[34][35][36] Out of organic compounds emissive in this region nanographenes can be heightened, which are characterized by outstanding photostability. [37,38] Low lasing threshold were determined for different structures, such as donor-π-acceptor type molecules based on benzothiadiazole, [39] pyrrolopyrrole aza-BODIPY, [40] or in perovskites. [41] We have utilized simple single dye-doped polymeric thin films for DFB and RL investigations in this work.…”