Slow Hopping and Spin Dephasing of Coulombically Bound Polaron Pairs in an Organic Semiconductor at Room Temperature

Polaron pairs are intermediate electronic states that are integral to the optoelectronic conversion process in organic semiconductors. Here, we report on electrically detected spin echoes arising from direct quantum control of polaron pair spins in an organic light-emitting diode at room temperature. This approach reveals phase coherence on a microsecond time scale, and offers a direct way to probe charge recombination and dissociation processes in organic devices, revealing temperature-independent intermolecular carrier hopping on slow time scales. In addition, the long spin phase coherence time at room temperature is of potential interest for developing quantum-enhanced sensors and information processing systems which operate at room temperature

The SEED Wellness Model: A Workplace Approach to Address Wellbeing Needs of Healthcare Staff During Crisis and Beyond

Workplace wellness has gained new meaning and significance in the healthcare workforce in the face of the COVID-19 pandemic. Healthcare workers across the world have carried the burden of responding to the public health crisis by having to work under new pressures and constantly changing environments, take on additional shifts, risk their own health and lives, and cope with the ongoing psychological and emotional strain. The purpose of this paper is to articulate a workplace wellness model applied across hospitals in the Illawarra Shoalhaven Local Health District, a regional area in New South Wales, Australia. The description of the development, components, and lessons learned from the SEED Wellness Model illustrates one possible solution about how to provide better care for the staff thus not only preventing staff burnout and turnover, but also creating lasting organizational benefits. The detailed model description can assist in developing a larger and more rigorous evidence-base to improve staff wellness in healthcare settings, both within Australia and internationally

Strongly exchange-coupled triplet pairs in an organic semiconductor

From biological complexes to devices based on organic semiconductors, spin interactions play a key role in the function of molecular systems. For instance, triplet-pair reactions impact operation of organic light-emitting diodes as well as photovoltaic devices. Conventional models for triplet pairs assume they interact only weakly. Here, using electron spin resonance, we observe long-lived, strongly-interacting triplet pairs in an organic semiconductor, generated via singlet fission. Using coherent spin-manipulation of these two-triplet states, we identify exchange-coupled (spin-2) quintet complexes co-existing with weakly coupled (spin-1) triplets. We measure strongly coupled pairs with a lifetime approaching 3 µs and a spin coherence time approaching 1 µs, at 10 K. Our results pave the way for the utilization of high-spin systems in organic semiconductors.Gates-Cambridge Trust, Winton Programme for the Physics of Sustainability, Freie Universität Berlin within the Excellence Initiative of the German Research Foundation, Engineering and Physical Sciences Research Council (Grant ID: EP/G060738/1)This is the author accepted manuscript. The final version is available from Nature Publishing Group at http://dx.doi.org/10.1038/nphys3908

Shallow recombination level in thin-film polycrystalline silicon on glass solar cells

Abstract not available

Anomalous temperature dependence of diode saturation currents in polycrystalline silicon thin-film solar cells on glass

10.1063/1.3131665Journal of Applied Physics10510-JAPI