利用光子晶体的光子禁带和光栅衍射效应可以提高LED的出光效率，扩大LED的应用范围。总结了光子晶体发光二极管的原理和典型器件。通过比较表明，与光子禁带效应相比，利用光栅衍射效应提高LED出光效率的方法更适用于电注入发光。因此可望用更廉价的方法在LED表面制造光子晶体，可通过光栅衍射效应来有效地提高其出光效率。

Combined with photonic crystals,the extraction efficiency of LED can be greatly enhanced by the effects of photonic band gap (PBG) and grating diffraction. Theoretical analysis on the photonic crystal LED and the corresponding typical devices are presented and summarized. It can be concluded that the means by use of the effcts of grating diffraction is more applicable to the LED under current injection. More low-cost fabrication methods are expected to integrate photonic crystal structures on surface of LED,and to enhance the extraction efficiency of LED by the effect of grating diffraction.