In Situ Spectroscopic Study of the Optomechanical Properties of Evaporating Field Ion Emitters

The possibility of measuring in situ operando photoluminescence spectroscopy within a photonic atom probe allows for the real-time study of the mechanical stress state within a field emitter either statically, as a function of the field-induced tensile stress, or dynamically, as a result of the evolution of the shape of the emitter upon its evaporation. Dynamic evolution results from the relaxation of strain induced by lattice mismatch and by the propagation of stress from the apex, while the morphology of the field emitter changes. Optomechanical information can be interpreted through the three-dimensional atomic scale images of the chemical composition of the emitter obtained through standard atom probe analysis. Here, the photoluminescence signal of a ZnO/(Mg,Zn)O quantum well allows for the local measurement of strain within the well and of the electrostatic field applied to the apex of the nanoscale field emitter.