Multistep resistive switching of doped Cu-TCNQ nanocrystals

Abstract

The resistive switching behavior of doped copper-(7,7,8,8-tetracyanoquinodimethane) (Cu-TCNQ) nanocrystals was different from that of bulk crystal. The doped Cu-TCNQ nanocrystals took the same crystal structure as bulk crystal (Cu:TCNQ = 1:1) in spite of the different composition ratio (Cu:TCNQ = 1.3:1). The excess amount of Cu resulted in the generation of TCNQ dianions (TCNQ2–) in Cu-TCNQ nanocrystals to keep the charge balance between TCNQ and excessive Cu, which led to multistep resistive switching behavior involving multistep charge transfer of TCNQ2–.