Growth, structures, properties, and applications of 2D materials comprising black phosphorous-like structures with highly in-plane anisotropy

Black phosphorus (BP), with its unique puckered honeycomb structure defined by armchair and zigzag chains, has gained significant attention owing to its tunable direct bandgap, high carrier mobility, and pronounced anisotropic behavior. These attributes make BP a leading candidate for next-generation electronics, optoelectronics, and sensors. However, its application is limited by significant challenges, such as instability under environmental conditions and the difficulty of synthesizing large-area, high-quality nanofilms. To overcome these obstacles and study their unique behaviors, researchers are turning to BP-like materials. The materials offer enhanced environmental stability and easier fabrication while retaining the beneficial properties of BP. BP analogs include Group V (phosphorus and arsenic) materials and Group IV-VI two-dimensional (2D) semiconductors, both showcasing distinctive advantages and expanding the horizons of 2D materials research. With tunable bandgaps, high carrier mobilities, and robust environmental stabilities, these materials open new pathways for the development of innovative applications and technologies. This review covers the crystal structures, properties, and synthesis techniques of BP and its analogs, providing a comparative analysis of their strengths and limitations. By highlighting the breakthroughs and challenges in this field, this paper aims to inspire further exploration into the design and application of these advanced materials, paving the way for transformative innovations in nanotechnology. This review highlights the specific family of BP-structural layered analogs including 2D P, As, Sb, Bi as well as tin and germanium monochalcogenides for demonstrating their unique in-plane anisotropic properties, functionalities as well as technical applications.