No abstract

A high luminescence and a high efficiency could be obtained for polymer light emitting diodes (PLEDs) after post annealing at an appropriate temperature. Calcium was used as the cathode material of light emitting diodes based on 2,3-dibutoxy-1,4-poly(phenylene vinylene) (DB-PPV). Ca diffused into polymer and degraded the performance after PLEDs were post annealed at various temperatures except for 120°C. The luminescence of PLEDs reached 5343 cd/m2 after annealing at 120°C. The corresponding efficiency under the condition was 3.04 cd/A. Both high luminescence and efficiency were greatly enhanced after PLEDs were annealed at 120°C.

Fluorinated amorphous carbon (a-C:F) thin film has been deposited by microwave electron cyclotron resonance plasma chemical vapor deposition (ECR-CVD) using CeHe and CHF3 as source gases. The result of x-ray photoelectron spectroscopy (XPS) shows that the mainbonds in the film as-deposited are C-C, C-F and CF2. The measurement of postive I-V property indicates that the conductance of the film presents Omic characteristic a t a lower electric field,and follows Schotty emission a t a higher electric field. 52.50G,82.80, 7 3 . 6 0~ PACS: