Simple One-Step Fabrication of Semiconductive Lateral Heterostructures Using Bipolar Electrodeposition

Unidirectional current flow is at the heart of modern electronics, which has been conceived by making p-n junctions or Schottky barriers between different kinds of materials. Within such elements, however, synthesis of thin film lateral heterostructures has so far remained challenging. Here, a one-step simple synthesis of p-type, n-type, and metallic lateral heterostructures using bipolar electrodeposition (BPE) technique is reported. Molybdenum oxides and sulfides with gradient of oxygen and sulfur are deposited at a metallic substrate. A lateral heterostructure is achieved with electrical properties that change from p- to n-type semiconductor and then to metal by moving in the plane of the layer. This effect is observed due to an increase in MoO-(2) and reduction of MoSx from one side to the other side of the structure. Finally, by transferring the layer onto a dielectric substrate, the current-voltage (I-V) characteristic of the layer is found to show a rectifying behavior with a low threshold of 0.45 V and a rectification of about 10 at relatively low applied voltages.