High Purity Single Photon Emission from In Situ Carbon Doped hBN Thin Films

Single photon emitters in two-dimensional layered hexagonal boron nitride are emerging as a promising platform for next-generation quantum technologies. However, control of defects, scalability, purity, and stability are key parameters that play a crucial role in their development. Here, we present a novel technique for generating pure defects in hBN thin films by incorporating carbon as a dopant using the pulsed laser deposition (PLD) method. The technique yields room-temperature polarized, stable, and bright single-photon emitters. Second-order photon correlation measurements further indicate a g²(0) value of 0.015±0.002, one of the lowest reported for room temperature quantum emitters and the lowest among any room temperature hBN quantum emitters, suggesting an impressively high purity of 98.5% for room-temperature single photon sources. Furthermore, detailed optical characterizations have been performed to study the nature of the emission. The results demonstrate a unique way to create carbon-related defects in hBN over a large-scale opening a new platform for quantum state engineering.