Polarity‐Modulated P‐Type WS 2 Nanotube Thickets for High‐Performance Photodetection

ABSTRACT Semiconductor photodetectors are vital for applications ranging from optical communication to intelligent imaging, yet realizing stable p‐type behavior in transition metal dichalcogenides (TMDs) remains a fundamental challenge. Here, we report a morphology‐driven strategy for polarity modulation through the synthesis of WS 2 nanotube thickets (NTTs) on SiO 2 /Si substrates using a simple and cost‐effective Au nanoparticle‐catalyzed chemical vapor deposition process. This previously unreported interlaced nanotube architecture enables scalable growth while intrinsically driving WS 2 into a robust p‐type state, overcoming its native n‐type nature without any external doping or surface treatment. Field‐effect transistors based on WS 2 NTTs display a hole mobility of 0.26 cm 2 V −1 s −1 and excellent photodetection at 650 nm over a wide temperature range of 10–300 K under high vacuum (5 × 10 −5 mbar). The device achieves a responsivity of 2.7 × 10 4 A W −1 , an external quantum efficiency of 6.3 × 10 6 %, and a detectivity of 1.6 × 10 13 Jones, with rise and fall times of 13 and 22 ms, respectively. Demonstrations in imaging, optical communication, and digit recognition confirm the versatility of this platform. This work presents a general polarity‐control approach for TMDs nanostructures and provides a promising platform for high‐performance p‐type optoelectronic devices.