Organic light-emitting device and preparation method thereof

Abstract

The invention belongs to the field of organic semiconductor materials, and discloses an organic light-emitting device and a preparation method of the organic light-emitting device. The organic light-emitting device comprises an anode substrate, a hole injection layer, a hole transfer layer, a light-emitting layer, a first electron transfer layer, an electron barrier layer, an electron injection layer and a cathode layer, wherein the anode substrate, the hole injection layer, the hole transfer layer, the light-emitting layer, the first electron transfer layer, the electron barrier layer, the electron injection layer and the cathode layer are stacked in sequence. The electron barrier layer is made of a doped mixed material formed by doping 4,7-diphenyl-1,10-phenanthroline or 1,2,4-triazole derivatives or N-aryl benzimidazole with phthalocyanines compounds according to the mass percent ranging from 1% to 5%. According to the organic light-emitting device, the electron barrier layer is crystallized to a certain extent to form an orderly arranged and stacked crystalline shape; the regular crystalline shape is beneficial to light scattering and reflection, and therefore light emitted to the two sides can return to the middle of the device after being scattered and reflected; moreover, light emitted to the top also can return to the bottom of the device by means of the reflection effect, and therefore the luminous efficiency of the device is improved.

Description

technical field [0001] The invention relates to organic semiconductor materials, in particular to an organic electroluminescent device and a preparation method thereof. Background technique [0002] In 1987, C.W.Tang and Van Slyke of Eastman Kodak Company in the United States reported a breakthrough in the research of organic electroluminescence. A high-brightness, high-efficiency double-layer organic electroluminescent device (OLED) has been prepared using ultra-thin film technology. In this double-layer structure device, the brightness reaches 1000cd / m at 10V 2 , its luminous efficiency is 1.51lm / W, and its lifespan is more than 100 hours. [0003] The principle of OLED light emission is based on the action of an external electric field, electrons are injected from the cathode to the lowest unoccupied molecular orbital (LUMO) of organic matter, and holes are injected from the anode to the highest occupied orbital (HOMO) of organic matter. Electrons and holes meet, recom...

AI Technical Summary

Problems solved by technology

[0004] In traditional light-emitting devices, an electron transport layer is generally prepared to increase the electron transport rate, and an electron injection layer is prepared to improve the electron injection efficiency, and the electron transport rate is usually lower than the hole transport rate. Two or three orders of magnitude. Therefore, the electron transport layer is usually n-doped, that is, the electron transport layer is doped with metal, such as doping Cs salt into Bphen and Li salt into TPBi to improve Electron transfer rate, this method is widely used, and can effectively increase the electron transfer rate, but the evaporation temperature is inconsistent between organic matter and inorganic matter, which brings difficulties to the evaporation temperature, and the rate increase is not high. In addition, the thickness cannot If it is made too thin (below 40nm), when the luminescent material is close to the metal electrode, the luminescent material will couple with the metal electrode, causing a loss to the excitons (surface plasmon waves), and the thickness is too thick (higher than 100nm), the number of defects increases, and the existence of electron traps will cause electrons or holes to enter the traps, resulting in a decrease in the probability of exciton recombination; all of these will affect the increase in electron transmission rate, which will lead to low luminous efficiency

Images