Tunable Electron-Injection Channels of Heterostructured ZnSe@CdTe Nanocrystals for Surface-Chemistry-Involved Electrochemiluminescence.

Tunable charge transfer in and out of nanocrystals (NCs) is crucial to their profound light-emitting applications. Herein a convenient strategy toward tunable electron-injection channels of NCs was achieved by partially coating highly passivated CdTe NCs with unperfected ZnSe shell. Potential- and spectrum-resolved electrochemiluminescence (ECL) characterizations proved that radiative charge recombination for ECL of the heterostructured ZnSe@CdTe NCs only occurred within CdTe core, whereas configurational ions in ECL solution could electrostatically or chemically change the surface states of both the ZnSe shell and the uncoated CdTe core, resulting in tunable electron-injection channels for ECL of ZnSe@CdTe NCs. S2- anion postponed the electron-injection channel for ECL of ZnSe@CdTe NCs from -1.44 to -1.58 V, Zn2+ cation presented two electron-injection channels for ECL at -1.53 and -1.22 V, respectively, whereas Cd2+ cation enabled three electron-injection channels for ECL at -1.53, -1.18, and -0.95 V, respectively. The "valve"-like role of configurational ions on the electron-injection channels of ZnSe@CdTe NCs is promising to design novel electrochemiluminophores.