Modulation of Single Photon Emission from Suspended 1L WSe₂ under Electrostatically Induced Strain.

Abstract

Tungsten diselenide (WSe₂) monolayers under strain are promising hosts for quantum emitters. To date, WSe₂ quantum emitter strain engineering has focused primarily on draping WSe₂ monolayers on patterned substrates and nanoindentation, which suffer from poor control over strain. In this work, we employ an electrostatic approach to dynamically control tensile strain in monolayer WSe₂ suspended over micron-scale cavities with a back gate contact. Room-temperature measurement of electrostatically induced deflection and photoluminescence at <i>T</i> = 100 K shows that a 0.22-0.26% increase in tensile strain can be achieved at modest gate voltages. Sharp localized emitters showed improvement in single photon purity from g⁽²⁾(0) = 0.55 ± 0.04 at 0 V to g⁽²⁾(0) = 0.40 ± 0.05 at -30 V due to strain-induced alignment of defect and dark exciton states and classical light background suppression.