Electrically regulating nonlinear optical limiting of metal-organic framework film

Regulating nonlinear optical (NLO) property of metal-organic frameworks (MOFs) is of pronounced significance for their scientific research and practical application, but the regulation through external stimuli is still a challenging task. Here we prepare and electrically control the nonlinear optical regulation of conductive MOFs Cu-HHTP films with [001]- (Cu-HHTP_[001]) and [100]-orientations (Cu-HHTP_[100]). Z-scan results show that the nonlinear absorption coefficient (β) of Cu-HHTP_[001] film (7.60 × 10^-6 m/W) is much higher than that of Cu-HHTP_[100] film (0.84 × 10^-6 m/W) at 0 V and the β of Cu-HHTP_[001] and Cu-HHTP_[100] films gradually increase to 3.84 × 10^-5 and 1.71 × 10^-6 m/W at 10 V by increasing the applied voltage, respectively. Due to 2D Cu-HHTP having anisotropy of charge transfer in different orientations, the NLO of MOFs film can be dependent on their growth orientations and improved by tuning the electrical field. This study provides more avenues for the regulation and NLO applications of MOFs.