Epitaxial Growth of 1D Te/2D MoSe₂ Mixed-Dimensional Heterostructures for High-Efficient Self-Powered Photodetector

Mixed-dimensional heterostructures provide additional freedom to construct diverse functional electronic and optoelectronic devices, gaining significant interest. Herein, highly-aligned pseudo-1D tellurium is epitaxially grown on 2D monolayer transition metal dichalcogenides (TMDs), including MoSe₂, MoS₂, and WS₂. A one-pot chemical vapor deposition (CVD) technique eliminates the normally required transfer steps, thereby producing mixed-dimensional heterostructures with an ultraclean interface. The controllable epitaxial growth of Te/TMD heterostructures are verified by Raman, scanning probe microscopy (SPM), and transmission electron microscopy (TEM) observation. The photoluminescence results indicate that the emission from TMDs is quenched in the heterostructure, confirming the efficient transfer of photogenerated carriers from TMDs to Te. Additionally, the mixed-dimensional p-n Te/MoSe₂ heterojunction photodetector presents self-driven behavior with high responsivity (328 mA W⁻¹), external quantum efficiency (79%), and specific detectivity (8.2 × 10⁹ Jones). The modified facile synthesis strategy and proposed growth mechanism in this study shed light on synthesizing mixed-dimensional heterojunctions. This opens avenues for fabricating functional devices with reduced sizes and high densities, further enabling miniaturization and integration opportunities.