Organic light emitting diode and manufacturing thereof

An organic electroluminescent device, and its preparation method are provided to improve driving voltage, consumption current, luminous efficiency and lifetime characteristic by modifying an electron transport layer. An organic electroluminescent device comprises a first electrode; an organic film which is located on the surface the first electrode, and comprises a light emitting layer and an electron transport layer; and a second electrode which is located on the surface the organic film, wherein the electron transport layer comprises any one selected from an organometallic complex containing an alkali metal and a compound represented by the formula 1. Preferably the organometallic complex containing an alkali metal is lithium quinolinolate or sodium quinolinolate.