New single photon sources by optoelectronic tailoring of 2D materials using low energy ion implantation

Monolayer thick transition metal dichalcogenides (TMDCs) with the chemical formula MX2 (M=Mo, W; X=S, Se), constitute a new class of direct bandgap semiconductors. Their remarkable physical properties resulting from their two dimensional (2D) geometry and lattice symmetry make them an exciting platform for developing photonic devices with new functionalities [1]. Monolayer TMDCs can be easily incorporated into electrically driven devices, which in turn can be coupled to optical microcavities or photonic circuits [2]. This work constitutes a proof-of-principle study to incorporate implanted TMDCs into non-classical single photon emitting diodes [3]. The development of such devices has far-reaching implications for emerging technologies such as quantum cryptography and quantum metrology. In order to make such devices a reality, methods of material modification for these materials, such as ultra-low energy (10-25 eV) ion implantation, must be developed [4,5]. Post-growth doping [6] of TMDCs offers an expanded selection of possible dopants compared to the popular method of doping via CVD growth. The technique allows for highly pure, clean and selective substitutional incorporation of dopants [7] and is also compatible with standard semiconductor processing. Ultra-low energy ion implantation is carried out using the ADONIS mass-selected ion beam deposition system at the University of Gottingen [8].