Effect of ion intercalation and electrochemisorption on nonlinear optical absorption of MoO3: A comparative study of six different ions

Abstract

Electrochemical modulation of nonlinear optical (NLO) absorption has recently garnered significant attention. In this work, we demonstrate the effective modulation of the third-order NLO absorption of layered molybdenum trioxide (MoO3) by cation intercalation. Upon application of different negative voltages to samples in different electrolytes, we observe varying degrees of enhancement in MoO3’s nonlinear absorption corresponding to different cations and different electrochemical processes. Cation intercalation of H[Formula: see text], Li[Formula: see text], Na[Formula: see text], K[Formula: see text], and Mg[Formula: see text] is found to be more effective in enhancing the nonlinear absorption of MoO3 than electrochemisorption of Al[Formula: see text] cations. Notably, Li[Formula: see text] intercalation leads to the most significant performance improvement, with an enhancement of 11.6 times and a nonlinear absorption coefficient of [Formula: see text][Formula: see text]cm[Formula: see text]GW[Formula: see text]. This improvement is ascribed to the increasing number of defect states in MoO3 during ion intercalation, which strengthens its saturation absorption behavior. Our work provides valuable insights into the electrically controlled NLO performance of MoO3 and can be applied to other similar materials.