Flat Panel Display Backlight Embedded With Quantum Dots

Semiconductor quantum dots are a new kind of inorganic fluorescent material,with several advantages of wide absorption spectrum, narrow emission spectrum, size adjustable emission and luminous stability compared with conventional organic fluorescent materials.Owing to the peculiar characters,semiconductor quantum dots have intensively investigated in flat panel display to improve the colour gamut.In this work,we design a quantum dots embedded backlight as light source for liquid crystals display with advantage of compact and low cost.Firstly, we introduce the development trends of the flat panel display industry and the research status of quantum dots,also the basic characteristics of quantum dots is described.Secondly, through the experiments on quantum dots apply to white LED,we find the quantum dots are susceptible to high temperature from the blue light LED which leads the instability and aging of devices. Thirdly, a new model is proposed to embed quantum dot micro structures into light guide plate for flat panel display. According to the ray tracing simulation with the Light Tools software a backlight system is built, the quantum dots slots are designed as isosceles trapezoid of 3mm topline,6.4mm baseline,3mm high,2mm thick, corresponding to the LED positions.When the angles of the trapezoidal groove is 60°for holding quantum dots,the backlight structure has the largest luminous flux. Further, the light efficiency is increased by 1 times with setting reflective PVC film in the groove side. In theory,the new structure backlight has two times brightness more than the existing flim structure of the quantum dots, but the amount of material used only to 1/133.Finally we demonstrate this with the 10.1inch TFT-LCD LED backlight and optical measurement,the brightness of new quantum dots backlight reached 4300 nit, the color temperature is 4110 K, and the optical performance is stable over time, it also can not be affected by high temperature of LED.The result shows the new model meet the requirements of the flat panel display products.