Room temperature triplet state spectroscopy of organic semiconductors

Organic light-emitting devices and solar cells are devices that create, manipulate, and convert excited states in organic semiconductors. It is crucial to characterize these excited states, or excitons, to optimize device performance in applications like displays and solar energy harvesting. This is complicated if the excited state is a triplet because the electronic transition is ‘dark’ with a vanishing oscillator strength. As a consequence, triplet state spectroscopy must usually be performed at cryogenic temperatures to reduce competition from non-radiative rates. Here, we control non-radiative rates by engineering a solid-state host matrix containing the target molecule, allowing the observation of phosphorescence at room temperature and alleviating constraints of cryogenic experiments. We test these techniques on a wide range of materials with functionalities spanning multi-exciton generation (singlet exciton fission), organic light emitting device host materials, and thermally activated delayed fluorescence type emitters. Control of non-radiative modes in the matrix surrounding a target molecule may also have broader applications in light-emitting and photovoltaic devices.United States. Dept. of Energy. Center for Excitonics (Award DE-SC0001088

The Minimum Balance at Risk: A Proposal to Mitigate the Systemic Risks Posed by Money Market Funds

This paper introduces a proposal for money market fund (MMF) reform that could mitigate systemic risks arising from these funds by protecting shareholders, such as retail investors, who do not redeem quickly from distressed funds. Our proposal would require that a small fraction of each MMF investor's recent balances, called the minimum balance at risk (MBR), be demarcated to absorb losses if the fund is liquidated. Most regular transactions in the fund would be unaffected, but redemptions of the MBR would be delayed for thirty days. A key feature of the proposal is that large redemptions would subordinate a portion of an investor's MBR, creating a disincentive to redeem if the fund is likely to have losses. In normal times, when the risk of MMF losses is remote, subordination would have little effect on incentives. We use empirical evidence, including new data on MMF losses from the U.S. Treasury and the Securities and Exchange Commission, to calibrate an MBR rule that would reduce the vulnerability of MMFs to runs and protect investors who do not redeem quickly in crises

Speaking to the people? Money, trust, and central bank legitimacy in the age of quantitative easing

Financial upheaval and unconventional monetary policies have made money a salient political issue. This provides a rare opportunity to study the under-appreciated role of monetary trust in the politics of central bank legitimacy which, for the first time in decades, appears fragile. While research on central bank communication with "the markets" abounds, little is known about if and how central bankers speak to "the people." A closer look at the issue immediately reveals a paradox: while a central bank's legitimacy hinges on it being perceived as acting in line with the dominant folk theory of money, this theory accords poorly with how money actually works. How central banks cope with this ambiguity depends on the monetary situation. Using the Bundesbank and the European Central Bank as examples, this paper shows that under inflationary macro-economic conditions, central bankers willingly nourished the folk-theoretical notion of money as a quantity under the direct control of the central bank. By contrast, the Bank of England’s recent refutation of the folk theory of money suggests that deflationary pressures and rapid monetary expansion have fundamentally altered the politics of monetary trust and central bank legitimacy.Die durch die Finanzkrise und die unkonventionellen Maßnahmen der Zentralbanken bewirkte Politisierung des Geldes erlaubt einen seltenen Einblick in den Zusammenhang zwischen Geldvertrauen und Zentralbanklegitimität. Die Kommunikation von Zentralbanken mit der breiten Öffentlichkeit – im Gegensatz zur gut erforschten Kommunikation mit Finanzmärkten bisher weitgehend vernachlässigt – sieht sich mit einem Dilemma konfrontiert. Einerseits hängt die Legitimität der Zentralbank davon ab, ob ihr Handeln den Maximen entspricht, die sich aus der in der Öffentlichkeit vorherrschenden Theorie des Geldes ableiten. Andererseits weicht diese Theorie in wichtigen Punkten von der tatsächlichen Funktionsweise des Geldsystems ab. Wie Zentralbanken mit diesem Dilemma umgehen, hängt von der allgemeinen geldpolitischen Situation ab. Anhand der Beispiele der Deutschen Bundesbank und der Europäischen Zentralbank wird argumentiert, dass Zentralbanker unter inflationären Bedingungen die Öffentlichkeit gerne in dem Glauben lassen, die Geldmenge sei vollständig von der Zentralbank kontrolliert. Die außergewöhnliche Initiative der Bank of England, die Öffentlichkeit von der Irrtümlichkeit dieser Vorstellung zu überzeugen, zeigt hingegen, dass deflationärer Druck und rapide geldpolitische Expansion das diskursive Verhältnis zwischen Geldvertrauen und Zentralbanklegitimität grundlegend verändert haben.1 Introduction 2 Money, trust and people Money: The political economy of money and (central) banking Trust: What does it mean to say that people have trust in money? People: Beyond methodological elitism 3 The folk theory of capitalist credit money The myth that all money is created equal (and thus non-hierarchical) The myth of banks as intermediaries and the myth of exogenous money 4 The politics of trust and legitimacy: From monetary restraint to monetary expansion Fighting inflation: The Bundesbank/ECB pretense of control over M3 Fighting deflation: The Bank of England’s insistence on non-control over M3 5 Conclusion Reference

Downhill from devaluation: The battle for sterling, 1967–1972

The devaluation of 1967 and the float of 1972 have become two of the key cornerstones in the analysis of sterling under the Bretton Woods system. Sterling’s fortunes between 1968 and 1972 have not been so well documented. This article uncovers new evidence about the pound for this period, including the British government’s contingency plans for blocking the sterling balances as a means to negate the weakness of sterling following the 1967 devaluation, the discussions with the United States on the reform of the international monetary system, and the preparations made for floating the pound