Resistance Switching and Memristive Hysteresis in Visible-Light-Activated Adsorbed ZnO Thin Films

Abstract

The discovery of resistance switching memristors marks a paradigm shift in the search for alternative non-volatile memory components in the semiconductor industry. Normally a dielectric in these bistable memory cells changes its resistance with an applied electric field or current, albeit retaining the resistive state based on the history of the applied field. Despite showing immense potential, sustainable growth of this new memory technology is bogged down by several factors including cost, intricacies of design, lack of efficient tunability, and issues with scalability and eco-friendliness. Here, we demonstrate a simple arrangement wherein an ethanol-adsorbed ZnO thin film exhibits orders of magnitude change in resistance when activated by visible light. We show that there exists two stable ohmic states, one in the dark and the other in the illuminated regime, as well as a significant delay in the transition between these saturated states. We also demonstrate that visible light acts as a non-invasive tuning parameter for the bistable resistive states. Furthermore, a pinched hysteresis I-V response observed in these devices indicate what seems to be a new type of memristive behaviour.

Field-induced p-n transition in yttria-stabilized zirconia

“…The first example consisted of coupled electronic and ionic charge transfer across a TiO 2 /TiO 2-δ interface under the action of a dc bias; the resulting conductivity change required application of a reverse bias to recover the initial state 3 . Since then, many materials with switchable and retainable resistance in both ‘ON’ and ‘OFF’ states have been studied in thin film form, including MgO 7 , ZnO 8 and VO 2 9,10 .…”

Memristor Behavior under Dark and Violet Illumination in Thin Films of ZnO/ZnO-Al Multilayers

“…where a pinched hysteresis loop can be obtained [1,7,26,36,40]. Characteristic I-V curves for different voltage frequencies were published previously in [26]; when voltage excitation frequency is diminished, the step between one conduction state and another is increased.…”

The Effect of Multi-Layer Stacking Sequence of TiOx Active Layers on the Resistive-Switching Characteristics of Memristor Devices

“…Based on the history of the applied bias, the memristors are switched between high-resistive state (HRS) and low-resistive state (LRS) by the modulation of the resistance of the active layer. For the active layers, many different material candidates have been investigated such as TiO 2 , HfO 2 , NbO 2 , TaO x , ZnO and Al 2 O 3 [11][12][13][14][15]. Also, for the formation of oxide active layers, deposition methods such as sputtering and anodizing have been utilized [16][17][18][19].…”