"Electrochromic performance of nanocomposite nickel oxide counter electrodes containing lithium and zirconium"

Feng Lin: Manuel Montano, Chixia Tian, Yazhou Ji, Dennis Nordlund, Tsu-Chien Weng, Rob G. Moore, Dane T. Gillaspie, Kim M. Jones, Anne C. Dillon, Ryan M. Richards, Chaiwat Engtrakul; Solar Energy Materials and Solar Cells, 07/15/14.

Additional Authors: Manuel Montano, Chixia Tian, Yazhou Ji, Dennis Nordlund, Tsu-Chien Weng, Rob G. Moore, Dane T. Gillaspie, Kim M. Jones, Anne C. Dillon, Ryan M. Richards, Chaiwat Engtrakul

Abstract:

Nickel oxide materials are suitable for counter electrodes in complementary electrochromic devices. The state-of-the-art nickel oxide counter electrode materials are typically prepared with multiple additives to enhance performance. Herein, nanocomposite nickel oxide counter electrodes were fabricated via RF magnetron co-sputtering from Ni–Zr alloy and Li2O ceramic targets. The as-deposited nanocomposite counter electrodes were characterized with inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and X-ray absorption spectroscopy (XAS). It was found that the stoichiometry, crystal structure and electronic structure of the nickel oxide-based materials could be readily tuned by varying the Li2O sputter deposition power level. Comprehensive electrochromic evaluation demonstrated that the performance of the nickel oxide-based materials was dependent on the overall Li stoichiometry. Overall, the nanocomposite nickel oxide counter electrode containing lithium and zirconium synthesized with a Li2O deposition power of 45 W exhibited the optimal performance with an optical modulation of 71% and coloration efficiency of 30 cm2/C at 670 nm in Li-ion electrolyte.