We demonstrate the effect of anionic polyelectrolyte as a cathode interlayer to enhance charge selectivity of the electrode/semiconductor junction of organic photodiodes. Poly(styrenesulfonate) (PSS) was used as a cathode interlayer to tune the energy level of an ITO/ZnO electrode, so that hole injection can be minimized while electron extraction can be maximized. Optimized photodiodes with a PSS interlayer showed lower and flatter dark current density curves compared to the reference devices, which implies that tunneling currents at the electrode/active layer interface were dramatically suppressed. Moreover, PSS as an interlayer enabled lower charge recombination yield, as confirmed by the ideality factor and linear dynamic range analysis. As a result, we could realize the near-ideal organic photodiodes with a high performance of specific detectivity up to 3.3 × 1012 Jones at −5 V.
Since 2003 Korea has experienced the highest suicide rate among OECD countries. One of the societal risk factors that triggers suicide is the contagious nature of suicide. This paper empirically examines the effect of celebrity suicide reports on subsequent copycat suicides, using daily suicide data and information of highly publicized suicide stories in Korea from 2005 to 2018. The findings from the Poisson regression model suggest that the number of public suicides soars after media reports on celebrity suicides. On average, the number of suicides in the population increased by 16.4% within just one day after the reports. Further analysis reveals that female and younger subgroups are more likely to be affected by celebrity suicides. Moreover, the public reacts more strongly to suicide incidents of celebrities of the same gender and even imitates the methods of suicide used by celebrities. This paper highlights the significance of careful and responsible media coverage of suicide stories to prevent copycat suicide. For policymakers, it is crucial to implement regulations not only for traditional media but also for new media where younger people can freely access unfiltered information.
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.