Light-Triggerable and Gate-Tunable Negative Differential Resistance in Small Molecules Heterojunction.

Negative differential resistance (NDR), a phenomenon in which the current decreases when the applied voltage is increased, is attracting attention as a unique electrical property. Here, we propose a broad spectral photo/gate cotunable channel switching NDR (CS-NDR) device. The proposed CS-NDR device has superior linear gate-tunable NDR behavior and highly reproducible properties compared to the previously reported NDR devices, as the fundamental mechanism of the CS-NDR device is directly related to a charge transport channel switching by the linear increase of the applied drain voltage. We also experimentally demonstrate that the photoinduced NDR behavior of the CS-NDR device was derived from the grain boundaries of dinaphtho[2;3-b:2',3'-f]-thieno[3,2- b ]thiophene. Furthermore, this work produces a 9 × 9 CS-NDR device array composed of 81 devices, providing the reproducibility and uniformity of the CS-NDR device. Finally, we successfully demonstrate the detection of text images with 81 CS-NDR devices using the proposed photo/gate cotunable NDR behavior.