Here we report the application of a conjugated copolymer based on thiophene and quinoxaline units, namely poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-altthiophene-2,5-diyl] (TQ1), to nanoparticle organic photovoltaics (NP-OPVs). TQ1 exhibits more desirable material properties for NP-OPV fabrication and operation, particularly a high glass transition temperature (T g) and amorphous nature, compared to the commonly applied semicrystalline polymer poly(3-hexylthiophene) (P3HT). This study reports the optimisation of TQ1:PC 71 BM (phenyl C 71 butyric acid methyl ester) NP-OPV device performance by the application of mild thermal annealing treatments in the range of the T g (sub-T g and post-T g), both in the active layer drying stages and post-cathode deposition annealing stages of device fabrication, and an in-depth study of the effect of these treatments on nanoparticle film morphology. In addition, we report a type of morphological evolution in nanoparticle films for OPV active layers that has not previously been observed, that of PC 71 BM nano-pathway formation between dispersed PC 71 BM-rich nanoparticle cores, which have the benefit of making the bulk film more conducive to charge percolation and extraction.

In this report, we are presenting highly efficient and humidity-resistant perovskite solar cells (PSCs) using two new small molecule hole transporting materials (HTM) made from a cost-effective precursor anthanthrone (ANT) dye, namely ACE-ANT-ACE and TPA-ANT-TPA. We have systematically compared our newly developed HTMs with the conventional 2,2´,7,7´-tetrakis(N,N´-di-pmethoxyphenylamino)-9,9´-spirbiuorene (Spiro-OMeTAD). ACE-ANT-ACE and TPA-ANT-TPA were used as a dopant free HTMs in mesoscopic TiO 2 /CH 3 NH 3 PbI 3 /HTM solid-state PSCs, and the

Organic electronic materials have been considered for a wide-range of technological applications. More recently these organic (semi)conductors (encompassing both conducting and semi-conducting organic electronic materials) have received increasing attention as materials for bioelectronic applications. Biological tissues typically comprise soft, elastic, carbon-based macromolecules and polymers, and communication in these biological systems is usually mediated via mixed electronic and ionic conduction. In contrast to hard inorganic semiconductors, whose primary charge carriers are electrons and holes, organic (semi)conductors uniquely match the mechanical and conduction properties of biotic tissue. Here, we review the biocompatibility of organic electronic materials and their implementation in bioelectronic applications.

Organic solar cells have the potential to become a low-cost sustainable energy source. Understanding the photoconversion mechanism is key to the design of efficient organic solar cells. In this review, we discuss the processes involved in the photo-electron conversion mechanism, which may be subdivided into exciton harvesting, exciton transport, exciton dissociation, charge transport and extraction stages. In particular, we focus on the role of energy transfer as described by Förster resonance energy transfer (FRET) theory in the photoconversion mechanism. FRET plays a major role in exciton transport, harvesting and dissociation. The spectral absorption range of organic solar cells may be extended using sensitizers that efficiently transfer absorbed energy to the photoactive materials. The limitations of Förster theory to accurately calculate energy transfer rates are discussed. Energy transfer is the first step of an efficient two-step exciton dissociation process and may also be used to preferentially transport excitons to the heterointerface, where efficient exciton dissociation may occur. However, FRET also competes with charge transfer at the heterointerface turning it in a potential loss mechanism. An energy cascade comprising both energy transfer and charge transfer may aid in separating charges and is briefly discussed. Considering the extent to which the photo-electron conversion efficiency is governed by energy transfer, optimisation of this process offers the prospect of improved organic photovoltaic performance and thus aids in realising the potential of organic solar cells.

In this work, we have reported two new, simple and cost-effective hole-transporting materials for perovskite solar cells. These novel structures namely N4, N4

In this report, two simple cost efficient solution processable small molecular hole transporting materials (HTMs) are synthesized and used successfully in inverted perovskite devices. These HTMs, namely (E)‐4,4'‐(ethene‐1,2‐diylbis(thiophene‐5,2‐diyl))bis(N,N‐bis(4‐methoxyphenyl)aniline) (TPA‐TVT‐TPA) and 4,4'‐(naphthalene‐2,6‐diyl)bis(N,N‐bis(4‐methoxyphenyl)aniline) (TPA‐NAP‐TPA), are designed by using triphenylamine methoxy as common end capping groups with thienylvinylenethienyl and naphthalene cores respectively. They possess good solubility in common organic solvents. Additionally, they have not only appropriate highest occupied molecular orbital energy levels for good hole injection ability but also sufficient lowest unoccupied molecular orbital for electron blocking capability. The power conversion efficiency (PCE) of these HTMs based devices is found to be of 16.32% for TPA‐TVT‐TPA and 14.63% for TPA‐NAP‐TPA. Particularly, TPA‐TVT‐TPA exhibits an impressive Voc of 1.07 V. The obtained performance is one of the highest performances in inverted perovskite layouts. The cut‐price and straightforward synthesis with elegant scale up makes these classes of materials important for the industry to produce high‐throughput printed perovskite solar cells for large area applications.

A new dopant free stable HTM using anthanthrone dye has been reported with 11.5% efficiency.

Fine‐tuning of the charge carrier polarity in organic transistors is an important step toward high‐performance organic complementary circuits and related devices. Here, three new semiconducting polymers, namely, pDPF‐DTF2, pDPSe‐DTF2, and pDPPy‐DTF2, are designed and synthesized using furan, selenophene, and pyridine flanking group‐based diketopyrrolopyrrole cores, respectively. Upon evaluating their electrical properties in transistor devices, the best performance has been achieved for pDPSe‐DTF2 with the highest and average hole mobility of 1.51 and 1.22 cm2 V−1 s−1, respectively. Most intriguingly, a clear charge‐carrier‐polarity change is observed when the devices are measured under vacuum. The pDPF‐DTF2 polymer exhibits a balanced ambipolar performance with the µh/µe ratio of 1.9, whereas pDPSe‐DTF2 exhibits p‐type dominated charge carrier transport properties with the µh/µe ratio of 26.7. Such a charge carrier transport change is due to the strong electron‐donating nature of the selenophene. Furthermore, pDPPy‐DTF2 with electron‐withdrawing pyridine flanking units demonstrates unipolar n‐type charge transport properties with an electron mobility as high as 0.20 cm2 V−1 s−1. Overall, this study demonstrates a simple yet effective approach to switch the charge carrier polarity in transistors by varying the electron affinity of flanking groups of the diketopyrrolopyrrole unit.