Voltage-controlled GaSe single photon emitters

The solid-state single photon emitter (SPE) is a critical building block for quantum information applications such as quantum communication, photonic quantum computing, and quantum metrology. SPEs in two-dimensional Van der Waals semiconductors have received extensive attention because of the potential for on-chip integration offered by monolayer materials with direct band gaps. Strain-induced quantum confinement has recently been used as a tool for deterministic localization of SPEs in multilayer GaSe. However, the engineering of GaSe SPEs’ brightness, photon purity and operating temperature remains a challenge. Here, we report on controlling the brightness and photon purity of strain localized GaSe SPEs through electrostatic doping. We show that the GaSe SPEs can operate up to 85 K with appropriate gating. Biexciton luminescence exceeds that of the exciton at higher temperatures, resulting in reduced single photon purity. Combining local strain control with electrostatic doping thus provides a flexible framework for the optimization of the brightness, photon purity and operating temperatures of GaSe SPEs.