Quantum dot photoluminescence as a versatile probe to visualize the interaction between plasma and nanoparticles on a surface

We experimentally demonstrate that the interaction between plasma and nanometer-sized semiconductor quantum dots (QDs) is directly connected to a change in their photoluminescence (PL) spectrum. This done by taking situ, high resolution, temporally resolved spectra of light emitted laser-excited QDs on an electrically floating sample exposed low pressure argon plasma. Our results show fast redshift PL emission peak indicating quantum-confined Stark effect due plasma-generated excess charges substrate near QD surface, while other plasma-induced (thermal ion) effects longer timescales could clearly be distinguished from these charging effects. The presented method open up pathways direct visualization understanding fundamental plasma–particle interactions nanometer length scales.