Organic electroluminescence device and preparing method thereof

Abstract

The invention discloses an organic electroluminescence device. The organic electroluminescence device comprises a substrate, a first electrode, a hole injection layer, a hole transmission layer, an organic light emitting layer, an electron transmission layer, an electron injection layer and a second electrode, wherein the substrate, the first electrode, the hole injection layer, the hole transmission layer, the organic light emitting layer, the electron transmission layer, the electron injection layer and the second electrode are sequentially stacked. The hole injection layer comprises two thin inorganic nano-rod films which are vertically stacked. The inclination angles of inorganic nano-rods of the thin inorganic nano-rod film at the side close to the substrate are smaller than the inclination angles of inorganic nano-rods of the thin inorganic nano-rod film at the side far away from the substrate. The thin inorganic nano-rod film with the smaller inclination angles is beneficial to the increase of the effective contact area between the hole injection layer and an adjacent electrode layer, the barrier height, from an anode to the hole injection layer, of a hole is effectively reduced, and the starting voltage and the working voltage are reduced. The thin inorganic nano-rod film with the larger inclination angles can effectively adjust the balance of electrons and the hole, the gap scattering property of the inclined nano-rods is used, so that on the premise that power efficiency is not sacrificed, the luminous efficiency is improved. The invention further discloses a preparing method of the organic electroluminescence device.

Description

technical field [0001] The invention belongs to the technical field of organic electroluminescence display, and in particular relates to an organic electroluminescence device and a preparation method thereof. Background technique [0002] As a new type of semiconductor display technology, organic electroluminescent technology has recently made great achievements in the fields of small and medium-sized mobile devices and large-sized displays. The light-emitting mechanism of organic light-emitting diode (OLED) is that under the action of an external electric field, electrons and holes are injected from the cathode and anode to the organic functional film, respectively, and the injected electrons and holes are transported from the electrons respectively. Layer and hole transport layer migrate to the light-emitting layer, recombine in the light-emitting layer to form excitons, and excitons radiatively transition to generate photons to complete the light-emitting process. [000...

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Problems solved by technology

[0003] In the prior art, an inorganic or P-type doped organic hole injection material is normally evaporated between the anode and the hole transport layer, and an amorphous hole injection layer is formed by atomic or molecular level stacking to reduce the hole density. The injection barrier provides a suitable step for hole injection, improves the hole injection ability, and reduces the turn-on voltage of the device. However, because the mobility of the hole transport material is much greater than that of the electron transport material, it only improves the hole unilaterally. Injection will easily lead to the imbalance of holes and electrons, which will reduce the luminous efficiency; in addition, most of the mass-produced organic hole injection materials are molten, easy to decompose when forming a film, and the decrease in purity will affect the stability of the device, and P-type dyes such as Seriously polluted chambers such as F4TCNQ

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