Fast Ultrahigh-Density Writing of Low Conductivity Patterns on Semiconducting Polymers

The exceptional interest in improving the limitations of data storage, molecular electronics, and optoelectronics has promoted the development of an ever increasing number of techniques used to pattern polymers at micro and nanoscale. Most of them rely on Atomic Force Microscopy to thermally or electrostatically induce mass transport, thereby creating topographic features. Here we show that the mechanical interaction of the tip of the Atomic Force Microscope with the surface of a class of conjugate polymers produces a local increase of molecular disorder, inducing a localized lowering of the semiconductor conductivity, not associated to detectable modifications in the surface topography. This phenomenon allows for the swift production of low conductivity patterns on the polymer surface at an unprecedented speed exceeding 20 $\mu m s^{-1}$; paths have a resolution in the order of the tip size (20 nm) and are detected by a Conducting-Atomic Force Microscopy tip in the conductivity maps.Comment: 22 pages, 6 figures, published in Nature Communications as Article (8 pages

The Party’s Over: Recounting the Past in American AIDS Plays

ABSTRACT: This article discusses the use of the past in regard to the gay sexual culture of the 1970s in three AIDS plays: Robert Chesley’s Jerker (1986), Victor Bumbalo’s Tell (1993) and Michael Kearns’s intimacies (1989). The themes explored—celebrating the sexual freedom of the past against contemporary criticism, commemorating places where gay men could meet for sexual encounters, and a sex continuum joining the busy nightlife of the past to the stern “here and now” of AIDS—stem from memory. Sex is only possible as a past activity and narrated as such in these plays, making them at the same time “obituary plays,” because they mourn sexual culture along with specific people, but also “memory plays,” because the memory that permeates them also omits some details, all the while magnifying others, in ways different from the plays of Tennessee Williams, who invented the term

Hollywood or Sodom: A conversation about Charles Busch’s rich career

Entretien avec Charles Busch, acteur/écrivain/chanteur, connu pour ses comédies, son jeu drag et son penchant pour le glamour hollywoodien. L’entretien a eu lieu le 2 février 2023 à New York, au domicile de l’auteur.Interview with Charles Busch, actor/playwright/singer, well-known for his comedies, his drag acting and his penchant for 1940s Hollywood glamour. The interview took place on February 2nd 2023, at the author’s New York home

Sexual Distancing: Remembrance of Sex Past in Robert Chesley’s Jerker

Inspiré du parallèle, souvent dressé de nos jours, entre la pandémie de Covid-19 et le sida, cet essai propose une lecture de Jerker or the Helping Hand de Robert Chesley, pour explorer la « distanciation sexuelle » parmi les hommes homosexuels, tels que dépeints dans les pièces américaines du milieu des années 1980. Le paramètre qu’introduit le théâtre, au-delà de la distanciation sexuelle physique, est le déplacement du sexuel dans le passé. En effet, dans Jerker, les deux personnages recourent systématiquement à la mémoire pour alimenter leurs fantasmes masturbatoires mais aussi pour retracer, dans un processus de régression, le désir homosexuel jusqu’à sa forme la plus primitive. Dans la mesure où le sexe y est une activité qui se reporte exclusivement au passé, Jerker (1986) propose un nouveau paradigme que les pièces sur le sida suivront pendant plusieurs années.Inspired by recent analogies drawn between the Covid-19 pandemic and the early stages of the AIDS epidemic, this essay addresses the ways in which AIDS plays attest to a “sexual distancing”, in particular with reference to Robert Chesley’s Jerker or the Helping Hand. Even though other plays also explore exclusion and stigmatisation, Jerker tackles not only physical sexual distancing but also the displacement of the sexual into the past. Indeed, both characters in Jerker resort systematically to their memory not only to feed their masturbatory fantasies but also to recount, through a process of regression, their homosexual desire down to its most primitive form. Inasmuch as sex acts in it refer exclusively to the past, Jerker (1986) advances a new paradigm that AIDS plays would follow for several years

Low-power supralinear photocurrent generation via excited state fusion in single-component nanostructured organic photodetectors

The integration of triplet–triplet annihilation (TTA) components as electrically and optically active elements in vertically-configured photoactive device architectures is a challenging task to achieve. Herein we present a simple methodology for incorporating a photon absorbing layer of the (2,3,7,8,12,13,17,18- octaethyl-porphyrinato)platinum(II) (PtOEP) metallorganic complex, as a self-TTA annihilator medium in a sandwich-like photodiode device structure. At low power illumination, the PtOEP photodiode exhibits photocurrent generation via the fusion of optically induced PtOEP excited states and it develops an open- circuit voltage (VOC) as high as 1.15 V. The structural and spectroscopic characterization of the nanostructured PtOEP photoactive layer in combination with electronic structure calculations identify PtOEP dimer species as the annihilating excited state responsible for the formation of charges. The participation of the fusion process in the mechanism of charge photogeneration manifests in the supralinear dependence of the short-circuit current density (JSC) on the incoming photoexcitation intensity, both when incoherent and coherent light are used for illuminating the PtOEP diodes. The photoresponse of the PtOEP device allows for highly selective and sensitive photodetection within the 500–560 nm narrow spectral range. At short-circuit conditions a power-law is observed in the dependence of the device responsivity on fluence. The observed response of the PtOEP photodiodes reveals a hitherto neglected mechanism of photocurrent generation in single-component organic electronic devices that is facilitated by TTA reactions. These findings pave the way towards the fabrication of next-generation electro-optical switches, ultrasensitive organic photodetectors, and TTA-sensitized solar cells with vertically-configured device structure

Bilayer Interdiffused Heterojunction Organic Photodiodes Fabricated by Double Transfer Stamping

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136265/1/adom201600784-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136265/2/adom201600784_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136265/3/adom201600784.pd

Improving the layer morphology of solution-processed perylene diimide organic solar cells with the use of a polymeric interlayer

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Photophysical Study of DPPTT-T/PC70BM Blends and Solar Devices as a Function of Fullerene Loading: An Insight into EQE Limitations of DPP-Based Polymers

Diketopyrrolopyrrole (DPP)-based polymers have been consistently used for the fabrication of solar cell devices and transistors due to the existence of intermolecular short contacts, resulting in high electron and hole mobilities. However, they also often show limited external quantum efficiencies (EQEs). In this contribution, the authors analyze the limitations on EQE by a combined study of exciton dissociation efficiency, charge separation, and recombination kinetics in thin films and solar devices of a DPP-based donor polymer, DPPTT-T (thieno[3,2-b]thiophene-diketopyrrolopyrrole copolymer) blended with varying weight fractions of the fullerene acceptor PC70BM. From the correlations between photoluminescence quenching, transient absorption studies, and EQE measurements, it is concluded that the main limitation of photon-to-charge conversion in DPPTT-T/PC70BM devices is poor exciton dissociation. This exciton quenching limit is related not only to the low affinity/miscibility of the materials, as confirmed by wide angle X-ray diffraction diffraction and transmission electron microscopy data, but also to the relatively short DPPTT-T singlet exciton lifetime, possibly associated with high nonradiative losses. A further strategy to improve EQE in this class of polymers without sacrificing the good extraction properties in optimized blends is therefore to limit those nonradiative decay processes