Normally, OLED devices will have relatively complex constructions to obtain higher energy efficiencies. However, these complex constructions intangibly increase the costs of production. The simplified structure can dramatically simplify the production process of OLED devices and thus have significant influences on the promoting of OLED. The simplified structure was firstly invented by J. Meyer and his colleagues in 2007. They created a simplified green phosphorescent device that has two organic layers, the efficiency of which can reach up to 40lm/W under 100cd/m2. In 2011, professor Z. H. Lu and his team found that ITO surface that after chlorine treatments can increase the power function to 6.1eV. In this way, extra HIL and HTL can be omitted, and consequently simplify the design and producing of OLED.
Tandem structure: Stephen R. Forresh suggested in a recent published report that using MoO3 in white phosphorescent devices as the connecting layer. The total efficiency is 22.7lm/W. M. V. Madahava Rao suggested to use pentacene/C60 PHJ as the connecting layer of tandem. Connecting layers used this material have better luminousness, weakening the effect of microcavity.
SPP enhanced OLED structure: 20%-40% light generated by OLED devices will be restricted in SPP. If the metal surface has similar construction as nanostructure, the restricted light can be sent out from SPP. A. Krumar created a layer of gold clusters of the surface of OLEDs through vacuum evaporation. Applying this technique in phosphorescent devices can increase the light efficiency by 2.8 times. A. Fujiki used special chemical method to form a thin layer of gold nano-particles on the surface of ITO, then deposited CuPc on the HTL. The thickness between metal and the light-emitting layer is adjustable. In theory, the light intensity can be increased by 20 times.
Quantum dots used on the OLED applications: Chang-Ching Tu and his colleagues used electrochemical etching methods to create silicon quantum dots, and proved that the silicon quantum dots (which should generate Blue-rays) usually sent out red rays due to Stokes shift caused by surface oxidation. In the “Solid State Project” of US Department of Energy, QD Vision created the enhanced quantum dots substrate for OLED solid state lighting and led lights, which can increase the light efficiency from 60% to 76%.