Preparation and optoelectronic properties of bulk black phosphorus crystals

In this paper, dense cylindrical shaped bulk black phosphorus (BBP)s are obtained by establishing a well-developed double growth zone technique through a chemical vapor phase transport (CVT) method. Extensive characterization tests confirm its high degree of orientation. XRD, SEM, TEM and Raman specturum are used to characterize the physical composition and structure of the prepared samples, confirming that the prepared BBP has good crystallinity and purity. Optical properties are evaluated, revealing distinct responses in UV–vis testing for black phosphorus (BP) of different sizes. Furthermore, the electrical properties of the bulk black phosphorus are measured, and it is found that the bulk black phosphorus is a P-type semiconductor. And the carrier mobility of the thin black phosphorus layer is 1233.81 cm2/V/S. The maximum Seebeck's coefficient along the column growth direction is 65.474 μV·K-1 when the temperature difference is within 100 K.