Wafer-scale patterned growth of type-II Dirac semimetal platinum ditelluride for sensitive room-temperature terahertz photodetection

As the lastly unexplored electromagnetic wave, terahertz (THz) radiation has been exploited in a plenty of contexts such as fundamental research, military and civil fields. Most recently, representative two-dimensional (2D) topological semimetal, platinum ditelluride (PtTe2) has attracted considerable research interest in THz detection due to its unique physical properties. However, to achieve practical applications, the low-cost, large-scale, controllable synthesis and efficient patterning of 2D materials are key requirements, which remain a challenge for PtTe2 and its photodetectors (PDs). Herein, a facile approach is developed to obtain wafer-scale (2-inches) patterned PtTe2 arrays using one-step tellurium-vapor transformation method and micro-Nano technology. PtTe2 PD arrays are fabricated with the as-grown PtTe2 arrays evenly distributed on a 2-inch wafer, exhibiting high conductivity (similar to 2.7 x 10(5) S m(-1)) and good electrical consistency. Driven by the Dirac fermions, PtTe2 PDs achieve a broadband (0.02-0.3 THz) response with a fast response speed (similar to 4.7 mu s), a high sensitivity (similar to 47 pW Hz(-1/2)) and high-resolution transmission THz-imaging capability, which displays the potential of large-area THz array imaging. These results are one step towards the practical applications of integrated PD arrays based on 2D materials.