In‐Plane 2H‐1T′ MoTe₂ Homojunctions Synthesized by Flux‐Controlled Phase Engineering

The fabrication of in‐plane 2H‐1T′ MoTe₂ homojunctions by the flux‐controlled, phase‐engineering of few‐layer MoTe₂ from Mo nanoislands is reported. The phase of few‐layer MoTe₂ is controlled by simply changing Te atomic flux controlled by the temperature of the reaction vessel. Few‐layer 2H MoTe₂ is formed with high Te flux, while few‐layer 1T′ MoTe₂ is obtained with low Te flux. With medium flux, few‐layer in‐plane 2H‐1T′ MoTe₂ homojunctions are synthesized. As‐synthesized MoTe₂ is characterized by Raman spectroscopy and X‐ray photoelectron spectroscopy. Kelvin probe force microscopy and Raman mapping confirm that in‐plane 2H‐1T′ MoTe₂ homojunctions have abrupt interfaces between 2H and 1T′ MoTe₂ domains, possessing a potential difference of about 100 mV. It is further shown that this method can be extended to create patterned metal–semiconductor junctions in MoTe₂ in a two‐step lithographic synthesis. The flux‐controlled phase engineering method could be utilized for the large‐scale controlled fabrication of 2D metal–semiconductor junctions for next‐generation electronic and optoelectronic devices.