Rylene dyes, made up of naphthalene units linked in peri-positions, are emerging as promising key building blocks to create π-functional materials. Chemists have found uses for these ribbonlike structures in a wide range of applications of optoelectronic devices. Because their structure combines two sets of six-membered electron-withdrawing dicarboxylic imide rings, rylene diimides exhibit enhanced solubility, excellent chemical and thermal stabilities, high electron affinities, and remarkable electron-transporting properties. Among them, perylene diimide (PDI) and naphthalene diimide (NDI) derivatives are important representatives improving the performance of electron-transporting technologies, relative to their p-channel counterparts. Pioneering works by Müllen and Langhals have inspired chemists to extend the π-conjugation along the peri-positions of rylene diimides, which generally results in impressive bathochromic shifts and a nearly linear increase in the extinction coefficient. In addition, in the past years, researchers have focused on π-expansion of NDI or PDI systems through bay-functionalization with carbocyclic and heterocyclic rings annulated onto the skeleton. However, chemists have rarely investigated lateral expansion via both bay- and nonbay-functionalization to construct homologous series of rylene arrays with different electronic delocalization and fine-tuned flexible linkage. This is probably due to the lack of effective procedures for the (multi) carbon-carbon formation and annulation of electron-deficient rylene imide units. In this Account, we discuss our recent progress in the design and synthesis of laterally expanded rylene dyes based on homocoupling and cross-coupling reactions of core-functionalized PDIs and NDIs to achieve novel high performance n-channel organic semiconducting materials. These new achievements offer us opportunities to learn fundamental issues about how chemical and physical properties alter with incremental changes in structure. We highlight synthetic methodology of transition-metal mediated coupling reactions (and/or C-H transformation) for singly linked, doubly linked, and fully conjugated triply linked oligoPDIs, and further for the construction of hybrid rylene arrays via bay- and/or nonbay-functionalization. In addition, we summarize the informative correlations between the molecular structures and their optoelectronic properties, especially the modulation of progressively red-shifted absorption maxima and positive shifts in the redox potentials. This decreases the energy gaps and increases the electron-accepting abilities through expansion of π-system, which has direct impacts on the compounds' potential applications in optoelectronic devices. Finally, we introduce the promising applications of these laterally expanded rylene dyes as exceptional high performance n-channel semiconductors in organic field-effect transistors (OFETs) and competitive candidates for non-fullerene acceptors in high efficient organic photovoltaic devices (OPVs).

Field-effect transistors based on carbon nanotubes have been shown to be faster and less energy consuming than their silicon counterparts. However, ensuring these advantages are maintained for integrated circuits is a challenge. Here we demonstrate that a significant reduction in the use of field-effect transistors can be achieved by constructing carbon nanotube-based integrated circuits based on a pass-transistor logic configuration, rather than a complementary metal-oxide semiconductor configuration. Logic gates are constructed on individual carbon nanotubes via a doping-free approach and with a single power supply at voltages as low as 0.4 V. The pass-transistor logic configurarion provides a significant simplification of the carbon nanotube-based circuit design, a higher potential circuit speed and a significant reduction in power consumption. In particular, a full adder, which requires a total of 28 field-effect transistors to construct in the usual complementary metal-oxide semiconductor circuit, uses only three pairs of n- and p-field-effect transistors in the pass-transistor logic configuration.

One of the most important factors that limits the efficiencies of bulk‐heterojunction organic solar cells (OSCs) is the modest open‐circuit voltage (Voc) due to their large voltage loss (Vloss) caused by significant nonradiative recombination loss. To boost the performance of OSCs toward their theoretical limit, developing high‐performance donor: acceptor systems featuring low Vloss with suppressed nonradiative recombination losses (<0.30 V) is desired. Herein, high performance OSCs based on a polymer donor benzodithiophene‐difluorobenzoxadiazole‐2‐decyltetradecyl (BDT‐ffBX‐DT) and perylenediimide‐based acceptors (PDI dimer with spirofluorene linker (SFPDI), PDI4, and PDI6) are reported which offer a high power conversion efficiency (PCE) of 7.5%, 56% external quantum efficiency associated with very high Voc (>1.10 V) and low Vloss (<0.60 V). A high Voc up to 1.23 V is achieved, which is among the highest values reported for OSCs with a PCE beyond 6%, to date. These attractive results are benefit from the suppressed nonradiative recombination voltage loss, which is as low as 0.20 V. This value is the lowest value for OSCs so far and is comparable to high performance crystalline silicon and perovskite solar cells. These results show that OSCs have the potential to achieve comparable Voc and voltage loss as inorganic photovoltaic technologies.