With the rapid development of human society, consumer electronics have brought marvelous changes to human daily life, but they are accompanied by the much higher demand of display quality and visual experience. Therefore, ideal conversion among the three primary colors—red (R), green (G), and blue (B)—in a single pixel has been a better way to avoid the insurmountable technical barrier of subpixel technology of modern displays. Electrofluorochromic (EFC) materials capable of a novel luminescent switching, open a powerful way to design optoelectronic devices for displays and information storage etc. Colorful EFC devices, especially emitting the ideal three primary colors without subpixel technology, have been a challenge for years. Herein, a long‐awaited single‐pixel device with RGB color is fabricated successfully based on proton‐coupled electron transfer. The RGB EFC device exhibits outstanding EFC properties, such as low turn‐on voltage (+1.0 and −1.0 V), large color gamut, and good stability (500 cycles for each color). Prototypes of colorful alphanumeric displays are well demonstrated in a facile way. The success of this new exploration of single‐pixel RGB EFC device not only provides the possibility of full‐color emission in EFC devices, but also will widely broaden the EFC system and their applications.

Altering the charge carrier transport polarities of organic semiconductors by molecular orbital distribution has gained great interest. Herein, we report two isomeric azulenedecorated naphthodithiophene diimide (NDTI)-based triads (e.g., NDTI-B2Az and NDTI-B6Az), in which two azulene units were connected with NDTI at the 2-position of the azulene ring in NDTI-B2Az, whereas two azulene units were incorporated with NDTI at the 6-position of the azulene ring in NDTI-B6Az. The two isomeric triads were excellently soluble in common organic solvents. Density functional theory calculations on the molecular orbital distributions of the triads reveal that the lowest unoccupied molecular orbitals are completely delocalized over the entire molecule for both NDTI-B2Az and NDTI-B6Az, indicating great potential for n-type transport behavior, whereas the highest occupied molecular orbitals are mainly delocalized over the entire molecule for NDTI-B2Az or only localized at the two terminal azulene units for NDTI-B6Az, implying great potential for p-type transport behavior for the former and a disadvantage of hole carrier transport for the latter. Under ambient conditions, solutionprocessed bottom-gate top-contact transistors based on NDTI-B2Az showed ambipolar field-effect transistor (FET) characteristics with high electron and hole mobilities of 0.32 (effective electron mobility ≈0.14 cm 2 V −1 s −1 according to a reliability factor of 43%) and 0.03 cm 2 V −1 s −1 (effective hole mobility ≈0.01 cm 2 V −1 s −1 according to a reliability factor of 33%), respectively, whereas a typically unipolar n-channel behavior is found for a film of NDTI-B6Az with a high electron mobility up to 0.13 cm 2 V −1 s −1 (effective electron mobility ≈0.06 cm 2 V −1 s −1 according to a reliability factor of 43%). The results indicate that the polarity change of organic FETs based on the two isomeric triads could be controlled by the molecular orbital distributions through the connection position between the azulene unit and NDTI.

Three new deep blue light emitters, bearing quinoxaline with different substituents (biphenyl/pyrene) at the 1-or 2-position, were synthesized by a Pd-catalysed coupling reaction in high yields, and were fully characterized by 1 H/ 13 C NMR spectroscopy, single crystal X-ray diffraction, and high-resolution mass spectrometry (HRMS). The designed molecules exhibit good thermal stability (T g > 452 o C). Single crystal X-ray diffraction indicated the compounds containing pyrene units exhibiting π-π stacking, and thus this family of compounds exhibited intramolecular charge transfer (ICT) and non-typical and aggregation-induced enhanced emission (AIEE) characteristics, possessing blue emission both in solution and in the aggregation (solid) state. Furthermore, a selected deep blue emitter was utilized as the emitting layer for the fabrication of doped organic light-emitting diode (OLED) devices, which afforded a deep blue electroluminescence (EL) peak at 428 nm with a narrow full width at half maximum (FWHM) of 57 nm, and the Commission Internationale de L'Eclairage (CIE) chromaticity coordinates of (0.15, 0.06).

It is special necessary to explore the influence of side group linked to pyrene core on the photophysical properties for constructing efficient pyrene-based blue-emitting materials. In this study, a series...