Seoul National University

About: Seoul National University is a education organization based out in Seoul, South Korea. It is known for research contribution in the topics: Population & Catalysis. The organization has 65879 authors who have published 138759 publications receiving 3715170 citations. The organization is also known as: SNU & Seoul-dae.

For fun and profit: Hedonic value from image interactivity and responses toward an online store

Abstract: With the use of an on-line retailer's Web site and an experimental method with 103 university students, statistical support through path analysis was found for positive influences of optimum stimulation level (preferred level of environmental stimulation) and recreational shopping on hedonic value (trying an image-interactivity feature of an apparel Web site as a stimulating experience). The Web site's mixandmatch image interactivity feature allowed creation of visual images of product combinations. The path-analysis model revealed significant paths between hedonic value and resulting emotional pleasure and arousal variables. A pattern of significant paths was also found between these three variables and global attitude, willingness to purchase, and willingness to patronize the on-line store. Theoretical and managerial conclusions are provided. © 2005 Wiley Periodicals, Inc.

Comprehensive defect suppression in perovskite nanocrystals for high-efficiency light-emitting diodes

Abstract: Electroluminescence efficiencies of metal halide perovskite nanocrystals (PNCs) are limited by a lack of material strategies that can both suppress the formation of defects and enhance the charge carrier confinement. Here we report a one-dopant alloying strategy that generates smaller, monodisperse colloidal particles (confining electrons and holes, and boosting radiative recombination) with fewer surface defects (reducing non-radiative recombination). Doping of guanidinium into formamidinium lead bromide PNCs yields limited bulk solubility while creating an entropy-stabilized phase in the PNCs and leading to smaller PNCs with more carrier confinement. The extra guanidinium segregates to the surface and stabilizes the undercoordinated sites. Furthermore, a surface-stabilizing 1,3,5-tris(bromomethyl)-2,4,6-triethylbenzene was applied as a bromide vacancy healing agent. The result is highly efficient PNC-based light-emitting diodes that have current efficiency of 108 cd A−1 (external quantum efficiency of 23.4%), which rises to 205 cd A−1 (external quantum efficiency of 45.5%) with a hemispherical lens. Guanidinium doping is shown to enhance the operation of perovskite nanocrystal light-emitting diodes.