Kinetic-thermodynamic modulation for configuration-selective growth of WS2/MoS2 heterojunctions toward sensitive photodetectors.

The controllable synthesis of two-dimensional (2D) heterojunctions with tailored structural features and low-defect interfaces remains challenging due to complicated growth kinetics. Here, a temperature-H2 synergistic modulation strategy is developed for the optional formation of lateral, vertical and hybrid WS2/MoS2 heterojunctions via a one-step chemical vapor deposition (CVD) method. The proposed strategy enables efficient control of precursor activation, nucleation sites and adatom diffusion, leading to selective heterojunction configurations with improved crystalline quality. Furthermore, phototransistors based on the as-grown heterostructures and the Al:HfO2 ferroelectric layer are fabricated to further investigate the electrical switching and photoresponse properties, elucidating the configuration-interface-performance correlation in WS2/MoS2 heterojunctions. The polarization-induced ferroelectric-gating cooperates with heterojunction interfacial engineering to generate localized field enhancement, modulating charge dynamics and band alignment. As a result, an outstanding detectivity of 1.55 × 1013 Jones is achieved. This work advances the fundamental understanding of heteroepitaxial growth and interlayer coupling in 2D heterostructures and paves the way for the development of future multifunctional nanoelectronic devices.