Explain the differences between radio frequency discharge in an excimer lamp and dielectric barrier discharge in an excimer lamp. It looks to me like with dielectric barrier discharge, there are microplasmas that form a thread-like output and that with radio frequency discharge, a fairly uniform glow discharge is created. What makes them different if they both consist of two external electrodes and a dielectric material in between? Please see my attached picture for diagram.
Qualitatively, you're absolutely correct. In DBD, micro-plasmas are formed (which are thread-like in structure, as you've already indicated). These thread-like plasmas generate irregular light emission (flickering light). In the case of a RF discharge, a plasma is formed uniformly between the dielectric material, resulting in a very uniform emission of light (spatially and temporarily), i.e., no flickering light.
Let's get a bit more quantitative, but not too technical, describing the concept of an excimer lamp, RFD and DBD. Depending on ...
This solution discusses the difference between Radio Frequency Discharge (RFD) and Dielectric Barrier Discharge (DBD) in an excimer lamp.