Negative differential resistance in polymer tunnel diodes using atomic layer deposited, TiO2 tunneling barriers at various deposition temperatures

Atomic layer deposition (ALD) presents a method to deposit uniform and conformal thin-film layers with a high degree of control and repeatability. Quantum functional devices that provide opportunities in low power molecular and organic based memory and logic via thin metal-oxide tunneling layer were previously reported by Yoon et al. [1]. Demonstrated here area polymer tunnel diodes (PIM with high negative differential resistance (NDR) using an ALD deposited tunneling layer grown between 250 degrees C 350 C. A critical relationship between deposition temperature, oxygen vacancy concentration and room temperature NDR is presented. In this work, for a TiO2 deposition temperature of 250 degrees C, the peak NDR voltage position (Vpeak) and associated peak current density Crpeak) are-4.3 V and-0.14 A/cm(2), respectively, with a PVCR as high as 1.69 while operating at room temperature. The highest PVCR recorded was 4.89 0.18 using an ALD deposition temperature of 350 degrees C. The key advantages of the ALD process used in fabrication of PTDs are increased repeatability and manufacturability. (C) 2017 Elsevier B.V. All rights reserved.