Investigation of Temperature‐Activated Charge‐Carrier Dynamics and Dielectric Relaxation in Fe, Cu–Doped CeO<sub>2</sub>
Manish Kumar Vishwakarma, Puneet Jain, Puneet Jain
Abstract
Cerium oxide (CeO 2 ) is a material with unique dielectric properties that make it a promising candidate for various applications. High electrical resistance and a wide bandgap of pristine CeO 2 limit its applicability in photovoltaics and photo‐electrocatalysis. CeO 2 is co‐doped with transition metals (Fe +2 /Fe +3 and Cu +2 ), which reduces its optical bandgap energy and electrical resistance. This study aims to investigate the dielectric relaxation behavior and charge‐carrier dynamics of Fe, Cu–CeO 2 . The enhanced charge‐carrier dynamics in the Fe, Cu–doped CeO 2 compared to pristine CeO 2 are reported. Using temperature‐dependent electrochemical impedance spectroscopy (TD‐EIS), the dielectric relaxation and carrier dynamics in pristine CeO 2 and Fe, Cu–doped CeO 2 in the temperature range 313–473 K along with the modulus spectroscopy are investigated. It is observed that Z ′ values reduced with the temperature, thus showing the negative temperature coefficient of resistance in the frequency range 6.28–1.005 10 5 radians s −1 . Furthermore, a correlated study of –Z″ and M″ shows the charge‐carrier relaxation behavior changes from ideal Debye type to non‐Debye type with temperature rise in Fe, Cu–doped CeO 2 .