We report here the development of high-performance p- and n-channel organic field-effect transistors (OFETs) and complementary circuits using inkjet-printed semiconducting layers and high-k polymer dielectric blends of poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) and poly(methyl methacrylate) (PMMA). Inkjet-printed p-type polymer semiconductors containing alkyl-substituted thienylenevinylene (TV) and dodecylthiophene (PC12TV12T) and n-type poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-dithiophene)} (P(NDI2OD-T2)) OFETs typically show high field-effect mobilities (μ(FET)) of 0.2-0.5 cm²/(V s), and their operation voltage is effectively reduced to below 5 V by the use of P(VDF-TrFE):PMMA blends. The main interesting result is that the OFET characteristics could be tuned by controlling the mixing ratio of P(VDF-TrFE) to PMMA in the blended dielectric. The μ(FET) of the PC12TV12T OFETs gradually improves, whereas the P(NDI2OD-T2) OFET properties become slightly worse as the P(VDF-TrFE) content increases. When the mixing ratio is optimized, well-balanced hole and electron mobilities of more than 0.2 cm²/(V s) and threshold voltages below ±3 V are obtained at a 7:3 ratio of P(VDF-TrFE) to PMMA. Low-voltage-operated (∼2 V) printed complementary inverters are successfully demonstrated using the blended dielectric and exhibit an ideal inverting voltage of nearly half of the supplied bias, high voltage gains of greater than 25, and excellent noise margins of more than 75% of the ideal values.
Fair and meaningful device performance comparison among luminescent solar concentratorphotovoltaic (LSC-PV) reports cannot be realized without a general consensus on reporting standards in LSC-PV research. Therefore, it is imperative to adopt standardized characterization protocols for these emerging types of PV devices that are consistent with other PV devices. This commentary highlights several common limitations in LSC literature and summarizes the best practices moving forward to harmonize with standard PV reporting, considering the
Recently, semitransparent luminescent solar concentrators (LSCs) have attracted considerable attention because they offer an easy and cost-effective route to harvest incident light. Various fluorophores including semiconducting quantum dots and organic dyes have been prepared and utilized for LSC fabrication. However, the narrow light absorption range, reabsorption losses, and limited photostability of the fluorophores still hinder the widespread use of LSCs under outdoor and indoor light conditions. Here, we rationally designed an LSC utilizing aggregation-induced emissive fluorophores (AIEgens) and an energy transfer (ET) strategy. We employ diketopyrrolopyrrole with triphenylamine moiety as a highly stable AIEgen that functions as an emissive ET acceptor in LSC; for a donor, we use tetraphenylethene containing triphenylamine moiety that shows good aggregation-induced emission features and excellent spectral overlap with the acceptor to yield an efficient ET process. A thin-film LSC device with an optimized donor:acceptor ratio (1:0.5) was fabricated. Under AM 1.5G solar spectrum, an LSC coupled with three side reflectors and a backside diffuser exhibits 18% optical conversion efficiency and a concentration factor of 1.18. Under indoor white LED illumination, the values were 27% and 1.68%, respectively. After exposed to intense UV radiations for 5 hours, the LSCs preserved 98% fluorescence which suggests their superior long-term photostability. Our results suggest that the combination of AIEgens and ET holds the potential for enhancing the efficiency of the device and extended stability of the fluorophores, two of the major requirements to allow industrial production and large-scale use of outdoor/indoor light harvesting LSCs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.