Dynamic Oscillation via Negative Differential Resistance in Type III Junction Organic/Two‐Dimensional and Oxide/Two‐Dimensional Transition Metal Dichalcogenide Diodes

Abstract Among many of 2D semiconductor‐based devices, type III PN junction diodes are given special attentions due to their unique function, negative differential resistance (NDR). However, it has been found uneasy to achieve well‐matched type III PN junctions from 2D–2D van der Waals heterojunctions. Here, the authors present other alternatives of type III heterojunctions, using 2D p‐MoTe 2 /organic n‐type dipyrazino[2,3‐f:2′,3′‐h]quinoxaline‐2,3,6,7,10,11‐hexacarbonitrile (HAT‐CN) and 2D p‐WSe 2 /n‐MoO x systems. Those junction diodes appear to well‐demonstrate static and dynamic NDR behavior via resonant tunneling and electron–hole recombination. Extended to an inverter circuit, p‐MoTe 2 /n‐HAT‐CN diode enables multilevel inverter characteristics as monolithically integrated with p‐MoTe 2 channel field effect transistor. The same NDR diode shows dynamic LC oscillation behavior under a constant DC voltage, connected to an external inductor. From p‐WSe 2 /n‐MoO x oxide diode, similar NDR behavior to those of p‐MoTe 2 /n‐HAT‐CN is again observed along with LC oscillations. The authors attribute these visible oscillation results to high peak‐to‐valley current ratios of their organic or oxide/2D heterojunction diodes.