Figure 5.

Red curves: 2θ–ω scan XRD patterns of 15 h Li₃PO₄-deposited (2–2.5 μm thick) LiCoO₂ thin films under different substrate bias potentials during sputtering. Deposition conditions were as follows: T_sub, 100 °C; RF power, 120 W; Ar, 20 sccm; O₂, 7 sccm; total pressure, 0.6 Pa; and target–substrate distance, 150 mm. XRD patterns before Li₃PO₄ deposition are also shown in blue curves, and the LiCoO₂ thickness is given on the right top of each panel. Right panels are magnified views around LiCoO₂ 003 in a linear intensity scale at potentials of 0.0, −1.0, and −2.0 V. Diffraction peaks marked by “*” in the left top panel indicate the O1 phase 00l.