Polarity-Modulated P-Type WS₂ Nanotube Thickets for High-Performance Photodetection

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 WS₂ nanotube thickets (NTTs) on SiO₂/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 WS₂ into a robust p-type state, overcoming its native n-type nature without any external doping or surface treatment. Field-effect transistors based on WS₂ NTTs display a hole mobility of 0.26 cm² 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 × 10⁴ A W⁻¹, an external quantum efficiency of 6.3 × 10⁶%, and a detectivity of 1.6 × 10¹³ 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.