The n-type doping of diamond is quite difficult, hindering the development of diamond-based electronic devices for decades. In this work, we have designed a boron–nitrogen co-doping technique to realize n-type diamonds. Basically, the activation energy of the donors has been greatly reduced by around 50%, thanks to the successful synthesis of the boron–nitrogen related donor-like complex by a fine control of the synthesis condition. Compared to the sole nitrogen doping scheme, it is found that the co-incorporation of boron elements is beneficial to a lot of aspects, including better crystalline quality, faster growth, higher nitrogen solubility, and stability. With the technique, a p-i-n diamond homojunction has been fabricated. A clear rectification behavior has been recorded, demonstrating that the current co-doping technique we proposed is a feasible path to the accessible n-type diamond.
