1：Experimental Design and Method Selection

The newly synthesized electron transporting materials ET1 and ET2 were purified by sublimation prior to spectroscopic measurement and device fabrication. All the electron transporting materials have been well-characterized by means of NMR in CDCl3 and FAB-Mass spectroscopy.

2：Sample Selection and Data Sources

Indium tin oxide (ITO)-coated glass was cleaned in an ultrasonic bath by the following sequence: in acetone, methanol, distilled water and isopropyl alcohol.

3：List of Experimental Equipment and Materials

Bruker, 400 MHz NMR,Perkin-Elmer Lambda 20 spectrometer,Acton Research Spectra Pro-150,CH instruments CHI619A cyclic voltammetry,Thermo gravimetric analyzer (Perkin Elmer Pyris 1TGA),Differential scanning calorimeter (Perkin Elmer Pyris 1DSC),KEITHLEY 2400 Source Meter,PHOTO RESEARCH Spectra Scan PR 650

4：Experimental Procedures and Operational Workflow

The following layers were deposited in the following sequence by evaporation from a heated boat under a vacuum of approximately 10-6 Torr; Without a vacuum break after the deposition of organic layers, the aluminum (Al) cathode was deposited at a rate of 10 °C sec-1.

5：Data Analysis Methods

The EL characteristics of all the fabricated devices were evaluated using a constant current source and a photometer at room temperature. Operational lifetime (or stability) of the devices were tested at the room temperature and at an initial luminance of 6000 cd m-2 by driving a constant current through the devices.