[1] Jiang X W, Zhao J W, Wu H et al. Design and optimization of flip-chip light-emitting diode with high light extraction efficiency[J]. Laser & Optoelectronics Progress, 55, 092302(2018).

[2] Seok M S, Yoo S, Choe J H et al. Light extraction efficiency enhancement using surface-structured light-emitting diodes with a subwavelength coating[J]. Journal of the Korean Physical Society, 68, 462-466(2016).

[3] Zhang H S, Zhu J, Zhu Z D et al. Surface-plasmon-enhanced GaN-LED based on the quasi-symmetrical planar waveguide structure[J]. Optics Communications, 311, 311-316(2013).

[4] Feng Q B, Li Y N, Li Q G et al. Lens array with double freeform surface for LED backlight in LCD imaging engine of helmet-mounted display[J]. Acta Optica Sinica, 35, 1123003(2015).

[5] Huang H W, Lai F I, Huang J K et al. Enhancement of light output power of GaN-based light-emitting diodes using a SiO2 nano-scale structure on a p-GaN surface[J]. Semiconductor Science and Technology, 25, 065007(2010).

[6] Babiker S G, Sid-Ahmed M O, Yong S et al. Polarized GaN-based light-emitting diode with a silver sub wavelength grating and dielectric layer[J]. Middle-East Journal of Scientific Research, 22, 193-198(2014).

[7] Matioli E, Rangel E, Iza M et al. High extraction efficiency light-emitting diodes based on embedded air-gap photonic-crystals[J]. Applied Physics Letters, 96, 031108(2010).

[8] Lu L F, Ye Z C. Extraction efficiency and polarization induced by photonic crystal structure on GaN-based blue LED[J]. Acta Photonica Sinica, 45, 1113001(2016).

[9] Huang H M, Hu H Y, Wang H et al. Enhanced light output of dipole source in GaN-based nanorod light-emitting diodes by silver localized surface plasmon[J]. Journal of Nanomaterials, 2014, 5(2014).

[10] Nakamura S, Chichibu S F[M]. Introduction to nitride semiconductor blue lasers and light emitting diodes(2000).

[11] Li Z Q, Wang C, Li W C et al. Improving LED luminescence properties by using Ag/P-GaN double grating[J]. Optics and Precision Engineering, 25, 1185-1191(2017).

[12] Okamoto K, Niki I, Shvartser A et al. Surface-plasmon-enhanced light emitters based on InGaN quantum wells[J]. Nature Materials, 3, 601-605(2004).

[13] Kwon M K, Kim J Y, Kim B H et al. Surface-plasmon-enhanced light-emitting diodes[J]. Advanced Materials, 20, 1253-1257(2008).

[14] Zhang H S, Zhu J, Zhu Z D et al. Surface-plasmon-enhanced GaN-LED based on a multilayered M-shaped nano-grating[J]. Optics Express, 21, 13492-13501(2013).

[15] Zhu J, Zhang H S, Zhu Z D et al. Surface-plasmon-enhanced GaN-LED based on the multilayered rectangular nano-grating[J]. Optics Communications, 322, 66-72(2014).

[16] Li L Q, Lü Y W. Surface-plasmon-enhanced light transmission intensity with a basic grating in GaN-based LED[J]. Journal of Semiconductors, 35, 46-51(2014).

[17] Li W C, Sha X P, Li Z Q et al. Emission enhancement of light-emitting diode by localized surface plasmon induced by Ag inserts in p-GaN and TiO2-Ag grating[J]. Plasmonics, 12, 1855-1860(2017).

[18] Ciesielski A, Skowronski L, Trzcinski M et al. Controlling the optical parameters of self-assembled silver films with wetting layers and annealing[J]. Applied Surface Science, 421, 349-356(2017).

[19] Lin M E, Sverdlov B N, Strite S et al. Refractive indices of wurtzite and zincblende GaN[J]. Electronics Letters, 29, 1759-1761(1993).

[20] Harris D C, Johnson L F, Seaver R et al. Optical and thermal properties of spinel with revised (increased) absorption at 4 to 5 μm wavelengths and comparison with sapphire[J]. Optical Engineering, 52, 087113(2013).

[21] Al-Kuhaili M F. Optical properties of hafnium oxide thin films and their application in energy-efficient windows[J]. Optical Materials, 27, 383-387(2004).

[22] Li Z Q, Liu T L, Bai L D et al. Surface-plasmon-enhanced GaN-LED based on nano-grating[J]. Infrared and Laser Engineering, 47, 0920005(2018).

[23] Wedge S, Barnes W L. Surface plasmon-polariton mediated light emission through thin metal films[J]. Optics Express, 12, 3673-3685(2004).

[24] Lu Y C, Chen Y S, Tsai F J et al. Improving emission enhancement in surface plasmon coupling with an InGaN/GaN quantum well by inserting a dielectric layer of low refractive index between metal and semiconductor[J]. Applied Physics Letters, 94, 233113(2009).