Embodiments of the present disclosure propose two methods for integrating vacancy centers (VCs) on semiconductor substrates for forming VC-based spin qubit devices. The first method is based on using a self-assembly process for integrating VC islands on a semiconductor substrate. The second method is based on using a buffer layer of a III-N semiconductor material over a semiconductor substrate, and then integrating VC islands in an insulating carbon-based material such as diamond that is either grown as a layer on the III-N buffer layer or grown in the openings formed in the III-N buffer layer. Integration of VC islands on semiconductor substrates typically used in semiconductor manufacturing according to any of these methods may provide a substantial improvement with respect to conventional approaches to building VC-based spin qubit devices and may promote wafer-scale integration of VC-based spin qubits for use in quantum computing devices.