LiF Layer at the Interface of Au Cathode in Organic Light-Emitting Devices: A Nonchemical Induced Carrier Injection Enhancement

Abstract

Au is not a suitable cathode material of organic light-emitting device because of its high work function resulting in poor electron injection. However, in present work, it is found that the performance of Au-cathode OLEDs can be efficiently improved by introducing a LiF buffer layer and with its optimal thickness can even be comparable to that of conventional Alcathode device. The relationship between the thickness of LiF layer and the performance improvement is investigated. The experimental results indicate a quite different mechanism of LiF thin layer from that of Al-cathode device, which is not chemicalreaction-mechanism-dominant. Other insulator material buffer layers such as Al 2 O 3 and BCP are also investigated.

The effect of Indium metal nanoparticles on the electronic properties of organic light emitting diodes (OLEDs)

“…So the charge recombination outside the emissive layer notably decreased. Normally, charge carriers of OLEDs without NPs tend to accumulate at an interface in the EL process due to massive charge injection from electrodes and low mobility in organic materials [19][20][21][22], which offers probability of exciplexes formation [11]. In this work emission of exiplex recombination was studied at the interface of HTL and HIL.…”

“…The Indium NPs were considered as an electron blocking layer to reduce the number of electrons inside the HTL. To study this effect, Au (Cu) was used as a high work function cathode to compare with Ag cathode [21,22]. Although a high work function cathode such as Au (Cu) is not a suitable cathode material in OLED devices, it can heavily influence carrier ratio [18].…”

Photoinduced Injection Enhancement in Fullerene-Based Organic Solar Cell Originates from Exciton–Electron Interaction

“…But reducing the height of tunneling barrier will enhance the injection current. According to the interfacial tunneling model, the height of tunneling barrier depends on three factors: charge accumulation in the organic layer (shown in Figure 4b), 26 thickness of the buffer layer (shown in Figure 4c), 27 and work function of the electrode (shown in Figure 4d). 28 This indicates that when the device A is illuminated, the charges in C 60 could also have an effect on the hole injection at cathode interface.…”

Hybrid OLEDs with CdSSe1–/ZnS core–shell quantum dots: An investigation of electroluminescence properties

“…5. Fermi levels of ITO, Al and HOMO, LUMO levels of other organic materials were taken from literature [12][13][14][15]. The energy band diagram of the QD OLED is shown in Fig.…”