Process for improving LED light emission efficiency

Abstract

When light is emitted from an LED chip, a significant part of light is reflected by the chip and an outside interface, and thus the loss of LED chip light is caused. When the chip emits blue light to excite phosphor power, the phosphor power emits yellow light, the yellow light easily enters into the chip, and the chip absorbs the yellow light and emits light which is not blue light. The invention provides a film used for raising the LED light emission efficiency and preventing the yellow light from entering into the LED chip to generate interference light and a method for preparing the film. The film is deposited at the surface of the LED chip, and the film is a double-layer anti-reflection film with the thickness of 1 / 4 of the wavelength of the blue light. For the yellow light, a film with certain thickness allows the yellow light to be totally reflected through the film without transmission light. A film plating method is a method of using electron gun evaporation deposition. The film is plated to the LED chip, and light emitting efficiency of the LED is effectively raised by 9%.

Description

technical field [0001] The patent of the present invention relates to a thin film and a thin film preparation method for improving the light extraction efficiency of LED chips and preventing disturbing light. technical background [0002] The semiconductor lighting industry has emerged globally. In the national medium and long-term scientific and technological planning strategic seminar, the "New Century Lighting Project" has been recommended as a major project, and the development of semiconductor lighting projects has entered a new era. At present, the luminous efficacy of power-type white LEDs is 100-120lm / W, but the luminous efficacy needs to be improved to truly replace incandescent lamps and fluorescent lamps and enter the general lighting market. On the one hand, it is required to continuously improve the quantum efficiency of LEDs in the production of chips, and it is also required to improve the light extraction efficiency as much as possible in the process of LED ...

AI Technical Summary

Problems solved by technology

One of the reasons for the low light extraction efficiency of existing LEDs is that the refractive index of the LED chip is relatively high. LED Chip Light Loss

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