V₂O₅ Nanosheets for Flexible Memristors and Broadband Photodetectors

Abstract

The synthesis of vanadium oxide family compounds is challenging because of their affinity to exist in different oxidation states and is further intensified by the lack of suitable techniques for their direct growth on flexible substrates, thus limiting their applications in flexible electronics. In this report, we demonstrate the one-step fabrication of a two-dimensional (2D) V2O5-based versatile papertronics (paper electronics) platform on a low-cost cellulose paper substrate and its application toward broadband photodetection and resistive memories. The porous nature of cellulose paper helps in the uniform growth of 2D V2O5 not only on the surface but also in bulk, thereby assisting in the easy diffusion of silver ions (Ag+) in the defect sites of V2O5, unlike in conventional flexible polymeric substrates, thereby assisting in the resistive switching mechanism. 2D V2O5 on a cellulose-paper-based memory exhibited an ON/OFF ratio of 3.5 × 102 and V set and V reset voltages of ∼+1 and −1 V, respectively, with excellent endurance and retention capacity of up to 500 cycles. The synthesized 2D V2O5 nanosheets exhibited broadband absorption ranging from ultraviolet (UV) to visible with an optical band gap calculated as 2.4 eV, making it suitable for broadband photodetection. Responsivities under UV- and visible-light illumination were found to be 31.5 and 20.2 mA/W, respectively, which are better than those of V2O5-based photodetectors fabricated using sophisticated methods. The fabricated broadband photodetector exhibited excellent mechanical stability with excellent retention in responsivity values over 500 cycles. The strategy outlined here presents a novel, low-cost, and one-step approach for fabricating devices on paper that find wide applications in flexible electronics.

Photo-rechargeable Zinc-Ion Capacitors using V2O5-Activated Carbon Electrodes

“…The slow dark current decays after switched off illumination of the photodetectors could be caused by oxygen vacancies related defects states. 31,32 The electrical measurements suggest that introduction of Ag with V2O5 enhance the overall photo-sensitivity as compared to the pristine counterpart.…”

Composite Memristors by Nanoscale Modification of Hf/Ta Anodic Oxides

“… 3 , 5 Their applications extend to logic circuits 6 , 7 and units, 8 neuromorphic systems, 9 , 10 sensors, 11 , 12 and photodetection. 13 The switching performance, from a high resistance state (HRS) to a low resistance state (LRS), depends on the selection of electrodes and active/oxide layers. This will define the conductive pathways formation, which is mediated by oxygen vacancies and/or cations and their field-activated movement inside the oxide.…”

Systematic Assessment of Visible-Light-Driven Microspherical V2O5 Photocatalyst for the Removal of Hazardous Organosulfur Compounds from Diesel

“…Pure V 2 O 5 shows broad absorption in the visible light region [38] and displays a strong absorption band at 500 nm [36]. The peak at the beginning of the visible spectrum at about 400 to 500 nm suggests that as-synthesized V 2 O 5 can be used as an efficient photocatalyst concealing the visible range [39]. The optical bandgap of V 2 O 5 was intended to be 2.41 eV using Tauc's plot presented in the inset of Figure 1d.…”