Photovoltage Dynamics of the Hydroxylated Si(111) Surface Investigated by Ultrafast Electron Diffraction

We present a novel method to measure transient photovoltage at nanointerfaces using ultrafast electron diffraction. In particular, we report our results on the photoinduced electronic excitations and their ensuing relaxations in a hydroxyl-terminated silicon surface, a standard substrate for fabricating molecular electronics interfaces. The transient surface voltage is determined by observing Coulomb refraction changes induced by the modified space-charge barrier within a selectively probed volume by femtosecond electron pulses. The results are in agreement with ultrafast photoemission studies of surface state charging, suggesting a charge relaxation mechanism closely coupled to the carrier dynamics near the surface that can be described by a drift-diffusion model. This study demonstrates a newly implemented ultrafast diffraction method for investigating interfacial processes, with both charge and structure resolution.Comment: 5 pages, 5 figure

Contest: Measuring Tech Emergence

This poster presents our approach to developing indicators of R&D emergence. Our indicator suite includes topical terms within a target domain indicated to draw accelerating attention for one-three years beyond the time series data analyzed. The purpose of the poster presentation is to lay out a contest that invites others to generate their own indicators of emerging R&D topics, and to invite participation in that contest

A Customer Satisfaction Model for Effective Fast Fashion Store Service

Part 2: Knowledge-Based ServicesInternational audienceThis paper proposed a customer satisfaction model to effectively manage staff priorities and service at fast fashion stores. An evaluation model of customer satisfaction was developed through multiple regression analysis of two measures. The first measure considered the difference between actual times and perceived times of customers’ behavioural processes while shopping to determine whether or not customers felt dissatisfied. The second measure identified factors which led to customer frustration through a multiple choice questionnaire. The proposed model was applied to multi-agent simulation to compare customer satisfaction levels