This paper presents a computational study of a new phase of phosphorus, called "blue phosphorus," which shares its layered structure with black phosphorus. The study shows that blue phosphorus has a wide fundamental band gap, exceeding 2 eV, and is nearly as stable as black phosphorus. Unlike black phosphorus, which has a narrow band gap, blue phosphorus is expected to be a semiconductor with high carrier mobility, making it a promising candidate for 2D electronic applications. The structure of blue phosphorus is similar to graphite, with a hexagonal in-plane structure and a bulk layer stacking that is closely related to graphite. The weak inter-layer interaction in blue phosphorus suggests that it can be easily exfoliated into quasi-2D structures. The study uses ab initio density functional theory (DFT) calculations to investigate the equilibrium structure, stability, and electronic properties of blue phosphorus. The results show that blue phosphorus has a larger binding energy than black phosphorus, indicating similar stability. The inter-layer interaction is weak, with a value of 6 meV/atom, which allows for easy exfoliation. The study also explores a possible transformation pathway from black to blue phosphorus, involving the introduction of dislocations in the black phosphorus structure. The electronic structure of blue phosphorus is found to be a semiconductor with an indirect band gap of approximately 2 eV. The band gap depends on the number of layers and in-plane stretching, and is sensitive to strain. The study also discusses the potential for blue phosphorus to be grown by chemical vapor deposition (CVD) on specific substrates, and suggests that it may form preferentially on substrates with hexagonal symmetry and a matching lattice constant, such as MoS₂ or the (0001) surfaces of Zr and Sc. The paper concludes that blue phosphorus is a promising new material for 2D electronics due to its wide band gap and high carrier mobility. It is expected to be a strong contender for future nano-electronic devices. The study also highlights the potential for blue phosphorus to coexist with black phosphorus on certain substrates, including stepped surfaces, to optimize the adlayer-substrate interaction.This paper presents a computational study of a new phase of phosphorus, called "blue phosphorus," which shares its layered structure with black phosphorus. The study shows that blue phosphorus has a wide fundamental band gap, exceeding 2 eV, and is nearly as stable as black phosphorus. Unlike black phosphorus, which has a narrow band gap, blue phosphorus is expected to be a semiconductor with high carrier mobility, making it a promising candidate for 2D electronic applications. The structure of blue phosphorus is similar to graphite, with a hexagonal in-plane structure and a bulk layer stacking that is closely related to graphite. The weak inter-layer interaction in blue phosphorus suggests that it can be easily exfoliated into quasi-2D structures. The study uses ab initio density functional theory (DFT) calculations to investigate the equilibrium structure, stability, and electronic properties of blue phosphorus. The results show that blue phosphorus has a larger binding energy than black phosphorus, indicating similar stability. The inter-layer interaction is weak, with a value of 6 meV/atom, which allows for easy exfoliation. The study also explores a possible transformation pathway from black to blue phosphorus, involving the introduction of dislocations in the black phosphorus structure. The electronic structure of blue phosphorus is found to be a semiconductor with an indirect band gap of approximately 2 eV. The band gap depends on the number of layers and in-plane stretching, and is sensitive to strain. The study also discusses the potential for blue phosphorus to be grown by chemical vapor deposition (CVD) on specific substrates, and suggests that it may form preferentially on substrates with hexagonal symmetry and a matching lattice constant, such as MoS₂ or the (0001) surfaces of Zr and Sc. The paper concludes that blue phosphorus is a promising new material for 2D electronics due to its wide band gap and high carrier mobility. It is expected to be a strong contender for future nano-electronic devices. The study also highlights the potential for blue phosphorus to coexist with black phosphorus on certain substrates, including stepped surfaces, to optimize the adlayer-substrate interaction.