<scp>Wafer‐scale</scp> patterned growth of <scp>type‐II</scp> Dirac semimetal platinum ditelluride for sensitive room‐temperature terahertz photodetection

Abstract

Abstract 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 (PtTe 2 ) 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 PtTe 2 and its photodetectors (PDs). Herein, a facile approach is developed to obtain wafer‐scale (2‐inches) patterned PtTe 2 arrays using one‐step tellurium‐vapor transformation method and micro‐Nano technology. PtTe 2 PD arrays are fabricated with the as‐grown PtTe 2 arrays evenly distributed on a 2‐inch wafer, exhibiting high conductivity (~2.7 × 10 5 S m −1 ) and good electrical consistency. Driven by the Dirac fermions, PtTe 2 PDs achieve a broadband (0.02–0.3 THz) response with a fast response speed (~4.7 μs), a high sensitivity (~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. image