Rapid advances in flexible optoelectronic devices necessitatetheconcomitant development of high-performance, cost-efficient, and flexibletransparent conductive electrodes (TCEs). This Letter reports an abruptenhancement in the optoelectronic characteristics of ultrathin Cu-layer-basedTCEs via Ar+-mediated modulation of the chemical and physicalstates of a ZnO support surface. This approach strongly regulatesthe growth mode for the subsequently deposited Cu layer, in additionto marked alteration to the ZnO/Cu interface states, resulting inexceptional TCE performance in the form of ZnO/Cu/ZnO TCEs. The resultantHaacke figure of merit (T (10)/R (s) ) of 0.063 & omega;(-1), 53% greater than that of the unaltered, otherwise identical structure,corresponds to a record-high value for Cu-layer-based TCEs. Moreover,the enhanced TCE performance in this approach is shown to be highlysustainable under severe simultaneous loadings of electrical, thermal,and mechanical stresses.