Organic Light-Emitting Diodes with Magnesium Doped CuPc as an Efficient Electron Injection Layer

Abstract

Bright organic electroluminescent devices are developed using a metal-doped organic layer intervening between the cathode and the emitting layer. The typical device structure is a glass substrate/indium-tin oxide (ITO)/copper phthalocyanine (CuPc)/N,N -bis-(1-naphthl)-diphenyl-1,1 -biphenyl-4,4 -diamine (NPB)/Tris(8-quinolinolato) aluminum(Alq3)/Mg-doped CuPc/Ag. At a driving voltage of 11 V, the device with a layer of Mg-doped CuPc (1:2 in weight) shows a brightness of 4312 cd/m 2 and a current efficiency of 2.52 cd/A, while the reference device exhibits 514 cd/m 2 and 1.25 cd/A.

Ecological Biosubstrates Obtained from Onion Pulp (Allium cepa L.) for Flexible Organic Light-Emitting Diodes

“…The measured maximum luminance of the onion FOLED was about 2062 cd m –2 at an applied voltage of 16.6 V. The current efficiency reached a maximum value of 2.1 cd A –1 at a current density of 85.3 mA cm –2 . The FOLED showed better efficiency than similar devices that use flexible substrates and Alq 3 as fluorescence emitting layers. − However, higher conversion efficiencies can be found in the literature using optimized architectures, for example, through the use of phosphorescent emitting layers and the insertion of rare earth complexes. − On the other hand, the reference OLED exhibited different characteristics, that is, a maximum luminance of about 4184 cd m –2 at an applied voltage of 10.8 V and a maximum current efficiency value of 1.1 cd A –1 at a current density of 93.9 mA cm –2 . Thus, the onion FOLED exhibited a higher current efficiency than the reference OLED.…”