Selective Generation of Luminescent Defects in Hexagonal Boron Nitride

Single photon emitters from atomic defects in crystals like hexagonal boron nitride (hBN) are vital for quantum technologies. Although various techniques are devised to obtain defects emission in hBN, simultaneous control over defects position, type, and emission spectrum has not been achieved yet. Here, ion implantation with 12C, 20Ne, and 69Ga are used to create a composite defects population with emission approximate to 820 nm. The correlation of Raman and photoluminescence (PL) spectroscopy helps to identify the defects' type. After selecting Ga as the ion species yielding the maximum emitter brightness, a strategy based on thermal annealing is developed to modify the composition of the induced defects. This results in an emitter ensemble with selected spectral properties, even when starting from different implantation conditions. Specifically, thermal annealing induces a defect transmutation from one type to another, shifting the emission wavelength from 820 to 625 nm. Moreover, sample patterning is combined with focused ion beam implantation and subsequent annealing in an efficient method to deterministically set the defects position as well as the PL spectral composition. These results offer a practical avenue to achieve in situ positioning and tuning of ensembles of emitters in hBN, promising for quantum information and sensing applications. Through a combination of ion implantation and thermal annealing, a dramatical wavelength tuning and enhancement of the emission from defects in hexagonal boron nitride (hBN) is demonstrated, whose atomic structures' insights are provided by Raman spectroscopy. Moreover, a focused ion beam allows to further control the position of the defects, with the potential of a full control over emitters for quantum applications. image