Enhanced electrochromism in short wavelengths for NiO:(Li, Mg) films in full inorganic device ITO/NiO:(Li, Mg)/Ta2O5/WO3/ITO

Abstract

Great interest has been drawn to the electrochromism demonstrated by inorganic materials, leading to various applications including smart windows and displays. NiO, as a cheap material, shows anodic electrochromism and is highly suitable for device applications in conjunction with W0 3 , but its strong optical absorbanoe has been largely overlooked. Herein, improved electrochromic properties in particular in short wavelengths was achieved by co doping of Mg and Li in NiO:(Ll, Mg) thin films grown using RF sputtering. Secondary Ion Mass Spectroscopy technique in combination with X ray Photoelectron Spectroscopy characterization provides direct evidence of the introduction of Mg as well as Li in the film Whatever the Li and Mg content, X Ray Diffraction and Raman spectroscopy studies only bring out the NiO face centered cubic rock sait structure. Electrochemical cycling shows pronounced anodic electro chromism for NiO:(Ll, Mg) thin films. Inorganic ail solid state monolithic multilayered devices are traditionally composed of a pair of electrodes with NiO and WOJ separated by Li containing electrolyte such as LiTa0 3 or LlNb0 3 sputtered from expensive but low efficient ceramic targets. Based on optimal NiO:(Ll, Mg) films, large switchable electrochromism both in visible (-58%) and ultraviolet band (-50%) is reconciled in electrochromic device Glass/ITO/NiO:(Li, Mg)(ra20sfW0 3 /ITO. The co doping of NiO with Mg and Li is capable of simultaneously widening the gap and avoiding the use of Li containing elec trolyte, through NiO pre lithiation. We believe the new, low cost approach would provide references with respect to practical applications desired for their successful commercial mass production.

Lithium trapping as a degradation mechanism of the electrochromic properties of all-solid-state WO3//NiO devices

“…Furthermore, a depth-dependent distribution is found in Li concentration. The present work on degradation mechanism in a full device is a continuation of earlier studies of ours [16][17][18][19] showing enhanced EC performance such as enlarged optical contrast, fast switching response and improved durability, WO 3 -1 and NiO-1 (from ECD1); WO 3 -2 and NiO-2 (from ECD2); and WO 3 -3 and NiO-3 (from ECD3), respectively.…”

Thickness Dependence of WO3 and NiOx Thin Films in All‐Solid‐State Complementary Electrochromic Devices

“…Deposition parameters and the thickness of WO 3 and NiO x films are shown in Table 3 . [ 22,33,42–45 ] The five‐layer CECD (30 mm × 30 mm), based on the ITO/WO 3 /UV−glue and LiClO 4 − PC/NiO x /ITO chain, was fabricated by assembling WO 3 and NiO x single layers of the optimum thickness in their initial states. The lithium‐based electrolyte was a type of composite polymer gel composed of LiClO 4 −PC (Li + ion concentration was 0.5 м and the volume of PC was 20 mL) and UV glue (20 mL), which were well stirred under covers for 120 min.…”

Effect of ion bombardment on the chemical properties of crystalline tantalum pentoxide films

“…Due to its low leakage current and high dielectric constant, tantalum pentoxide has been used in storage capacitors, insulators, catalysts, gas detectors, and memory devices [1][2][3][4] . In addition to its electrical properties, Ta 2 O 5 possesses high refraction index (n = 2.18 at λ = 550 nm) and a wide band gap of ∼4.0 eV which makes it an excellent material for optical and electrochromic applications [5][6][7][8][9][10][11][12] .…”