On the optical measurement of microparticle charge using quantum dots

Abstract

We investigated the possibility of using a layer of quantum dots (QDs) deposited on the microparticle surface for the measurement of the charge the microparticle acquires when immersed into a plasma. To that end, we performed the calculations of the Stark shift of the photoluminescence spectrum of QDs caused by the fluctuating local electric field. In our calculations, we assumed the plasma-delivered surplus electrons to be distributed on the surface of a microparticle. According to our calculations, the Stark shift will acquire measurable values when the lifetime of the quasi-stationary configuration of the surplus electrons will be determined by their diffusion along the surface. Experiments with flat QD-covered floating plasma-facing surfaces suggest that measurable Stark shift of the photoluminescence spectrum can be achieved. Based on our model, modern microscopic plasma-surface interaction theories and analysis of the experiments, we suggest the possible design of the charge microsensor, which will allow to measure the charge accumulated on its surface by means of visible-light optics.

References in corpus (9)

• Mie scattering by a charged dielectric particle
• Electron surface layer at the interface of a plasma and a dielectric wall
• Particle charge in PK-4 dc discharge from ground-based and microgravity experiments
• Optical signatures of the Charge of a Dielectric Particle in a Plasma
• Dust as probes: determining confinement and interaction forces
• Capacitively-coupled rf discharge with a large amount of microparticles: spatiotemporal emission pattern and microparticle arrangement
• Features of electromagnetic waves in a complex plasma due to surface plasmon resonances on macroparticles
• Infrared light extinction by charged dielectric core-coat particles
• Quantum dot photoluminescence as a versatile probe to visualize the interaction between plasma and nanoparticles on a surface