Fig. 2: Site-controlled quantum emitter array via strain and defect engineering.
a Schematic of the fabricated structure and the optical dark-field image of the sample. An stack of h-BN/WSe2/h-BN is transferred on a SiO2 nanopillar array. Bright emission is observed from the top of the pillars due to exciton funneling. Next, top of the pillars are irradiated (e− arrows) to induce structural defects. b PL spectra of unstrained WSe2 defect-bound excitons as a function of irradiation intensity from N1 = 105 electrons/μm to N2 = 106 electrons/μm 10 μW excitation power. c Spectrally integrated PL map of strained and irradiated sites for wavelengths above 775 nm, showing the bright emission associated with single-photon emitters. Some sites host more than one emitter and have reached saturation incident count. The maps resemble the Gaussian spot size of excitation laser due to the localized nature of the emitters. d PL spectrum (1 μW excitation power) captured from different pillar sites showing the sharp emission lines (75 µeV average linewidth) associated with SPEs. Note that many of the sharp emission lines appear in pairs, which indicates the possible formation of exciton-biexciton pairs. e Histogram of number of quantum emitters measured per site by irradiating with e-beam intensity of 105 electrons/μm2. f Histogram of number of quantum emitters measured per site for 106 electrons/μm2.
