Black phosphorus (black P), a two-dimensional layered material, has regained significant attention in the past decade due to its unique properties and potential applications in nanoelectronics and nanophotonics. First synthesized in 1914, black P was rediscovered as a 2D material, showing a direct band gap that varies from 0.3 to 2 eV depending on its thickness. It exhibits high carrier mobility and anisotropic in-plane properties, making it promising for novel applications different from graphene and transition metal dichalcogenides (TMDs). Black P has three crystalline structures, with the semiconducting puckered orthorhombic structure being of particular interest. Its single- and few-layer forms can be isolated using techniques like micromechanical exfoliation, leading to unique two-dimensional properties. Black P has shown potential in various applications, including optoelectronics, thermoelectrics, and gas sensing. Its band gap can be tuned through strain and layer number, enabling a wide range of applications. The material's anisotropic properties allow for the design of novel electronic and photonic devices. Recent studies have demonstrated high mobility and on-off ratio in black P transistors, with some achieving GHz frequency performance. However, black P is unstable in air and requires encapsulation to maintain its properties. Research is ongoing to develop large-scale synthesis methods and improve stability through passivation techniques. Future research directions include exploring black P's potential in optoelectronics, thermoelectrics, and flexible electronics. The material's unique properties, such as its anisotropic transport and high mobility, make it a promising candidate for various applications. Despite challenges in stability and synthesis, black P is considered a key material for future high-performance electronics and optoelectronics. Ongoing studies aim to address these challenges and further explore the material's potential in both fundamental research and practical applications.Black phosphorus (black P), a two-dimensional layered material, has regained significant attention in the past decade due to its unique properties and potential applications in nanoelectronics and nanophotonics. First synthesized in 1914, black P was rediscovered as a 2D material, showing a direct band gap that varies from 0.3 to 2 eV depending on its thickness. It exhibits high carrier mobility and anisotropic in-plane properties, making it promising for novel applications different from graphene and transition metal dichalcogenides (TMDs). Black P has three crystalline structures, with the semiconducting puckered orthorhombic structure being of particular interest. Its single- and few-layer forms can be isolated using techniques like micromechanical exfoliation, leading to unique two-dimensional properties. Black P has shown potential in various applications, including optoelectronics, thermoelectrics, and gas sensing. Its band gap can be tuned through strain and layer number, enabling a wide range of applications. The material's anisotropic properties allow for the design of novel electronic and photonic devices. Recent studies have demonstrated high mobility and on-off ratio in black P transistors, with some achieving GHz frequency performance. However, black P is unstable in air and requires encapsulation to maintain its properties. Research is ongoing to develop large-scale synthesis methods and improve stability through passivation techniques. Future research directions include exploring black P's potential in optoelectronics, thermoelectrics, and flexible electronics. The material's unique properties, such as its anisotropic transport and high mobility, make it a promising candidate for various applications. Despite challenges in stability and synthesis, black P is considered a key material for future high-performance electronics and optoelectronics. Ongoing studies aim to address these challenges and further explore the material's potential in both fundamental research and practical applications.