Influence of the Molecular Weight and Size Dispersion of the Electroluminescent Polymer on the Performance of Air-Stable Hybrid Light-Emitting Diodes

Abstract

The influence of the chain length and the molecular weight distribution of the electroluminescent polymer on the carrier transport properties and morphology of air stable Hybrid Light Emitting Diodes is reported. It is found that variations between diverse as-received commercial batches play a major role in the performance of the devices, whose maximum luminance can differ up to two orders of magnitude. Through complementary opto-electronic, structural and morphological characterization techniques we provide insights into the relationship between charge dynamics and the structure of polymeric electroluminescent materials. The carrier dynamics are found to be dominated by both the polymeric chain length and the hole transport, which in turn, is dependent on the concentration of trap states.Furthermore, the chain length is seen to affect the morphology of the active layer.

Inverted Hybrid Light-Emitting Diodes Using Carbon Dots as Selective Contacts: The Effect of Surface Ligands

“…All devices were prepared using optimized conditions as reported previously. 28 Figure 6 shows the corresponding current and luminance versus voltage curves for all the devices fabricated using the different C-Dots. Table 5 summarizes the most relevant parameters including the values obtained for a device without HTL included for comparison purposes.…”

“…Once the optical and electrical characterization of the different C-Dots was done, we focused on the fabrication of inverted HyLEDs using the C-Dots as the hole transport material (HTM). All devices were prepared using optimized conditions as reported previously Figure shows the corresponding current and luminance versus voltage curves for all the devices fabricated using the different C-Dots.…”