Light output enhancement of a GaN-based light emitting diode by polymer film imprinting

Wang, Z M; Luo, Xianjia; Wang, S; Luo, Chunxiong; Sun, Minwei; Bao, Kui; Zhang, B; Zhang, G Y; Wang, Y G; Chen, Y; Ji, Hang; Ouyang, Qi

doi:10.1088/0268-1242/22/3/018

Cited by 6 publications

(4 citation statements)

References 21 publications

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“…Fortunately, the external quantum efficiency of GaN-based LEDs can easily be improved by enhancing the escape probability of the trapper photons. Methods that can increase the external quantum efficiency include reducing the surface roughness [3], utilizing photonic crystals [4], patterning the sapphire substrate [5], and imprinting techniques [6,7]. These methods introduce a relative roughness interface between the air and the LED chip so that the opportunity for photons to escape from inside the GaN chip increases.…”

Section: Introductionmentioning

confidence: 99%

Demonstration of a simplified optical mouse lighting module by integrating the non-Lambertian LED chip and the free-form surface

Pan

2012

Appl. Opt.

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A cost-effective, high-throughput, and high-yield method for the efficiency enhancement of an optical mouse lighting module is proposed. We integrated imprinting technology and free-form surface design to obtain a lighting module with high illumination efficiency and uniform intensity distribution. The imprinting technique can increase the light extraction efficiency and modulate the intensity distribution of light-emitting diodes. A modulated light source was utilized to add a compact free-form surface element to create a lighting module with 95% uniformity and 80% optical efficiency.

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Section: Introductionmentioning

confidence: 99%

Demonstration of a simplified optical mouse lighting module by integrating the non-Lambertian LED chip and the free-form surface

Pan

2012

Appl. Opt.

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“…Fortunately, the external quantum efficiency of GaN-based LEDs can easily be improved by suppressing the total internal reflection. The methods which can enlarge the escape opportunity of photon inside GaN substrate included the surface roughness [3], the photonic crystals [4], the pattern sapphire substrate [5] and the imprinting technique [6,7]. Those methods introduced a relative roughness interface between air and LED chip so that the effect of TIR was suppressed.…”

Section: Introductionmentioning

confidence: 99%

Integration of Non-Lambertian LED and Reflective Optical Element as Efficient Street Lamp

Pan¹,

Tu²,

Sun³

et al. 2010

Opt. Express

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A cost effective, high throughput, and high yield method for the increase of street lamp potency was proposed in this paper. We integrated the imprinting technology and the reflective optical element to obtain a street lamp with high illumination efficiency and without glare effect. The imprinting technique can increase the light extraction efficiency and modulate the intensity distribution in the chip level. The non-Lambertian light source was achieved by using imprinting technique. The compact reflective optical element was added to efficiently suppress the emitting light intensity with small emitting angle for the uniform of illumination intensity and excluded the light with high emitting angle for the prevention of glare. Compared to the conventional street lamp, the novel design has 40% enhancement in illumination intensity, the uniform illumination and the glare effect elimination.

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“…PDMS has unique characteristics such as excellent physical and chemical properties, good biocompatibility, low cost and simple fabrication with high replication fidelity [2][3][4]. PDMS is an elastomer with the following properties: Young's modulus of ∼750 kPa [5], dielectric strength of 14 kV mm −1 [6], thermal conductivity of 0.16 W (m K) −1 [6], refractive index of 1.42 [7], optical transparency down to 300 nm wavelength [3] and high gas permeability (O 2 , 79 × 10 −7 (cm 3 cm) (s cm 2 kPa) −1 ); CO 2 , 405 × 10 −7 (cm 3 cm) (s cm 2 kPa) −1 ) [8]. It is chemically inert and non-flammable, and has a low surface free energy of 22 mJ m −2 [9], as a result of which it is hydrophobic in nature.…”

Section: Introductionmentioning

confidence: 99%

Dry etching of polydimethylsiloxane using microwave plasma

Hwang¹,

Oh²,

Jung³

et al. 2009

J. Micromech. Microeng.

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This paper presents a new polydimethylsiloxane (PDMS) dry-etching method that uses microwave plasma. The applicability of the method for fabricating microstructures and removing residual PDMS is also verified. The etch rate of PDMS was dominantly influenced by the gas flux ratio of CF 4 /O 2 and the microwave power. While the PDMS etch rate increased as the flux ratio of CF 4 was increased, the etch rate decreased as the flux ratio of O 2 was increased. The maximum etch rate of 4.31 μm min −1 was achieved when mixing oxygen (O 2 ) and tetrafluoromethane (CF 4 ) at a 1:2 ratio at 800 W power. The PDMS etch rate almost linearly increased with the microwave power. The ratio of the vertical etch rate to the lateral etch rate was in a range of 1.14-1.64 and varied with the gas fluxes. In consideration of potential applications of the proposed PDMS etching method, array-type PDMS microwells and network-type microprotrusion structures were fabricated. The contact angle was dramatically increased from 104 • (non-etched PDMS surface) to 148 • (etched PDMS surface) and the surface was thereby modified to be superhydrophobic. In addition, a thin PDMS skin that blocked holes and PDMS residues affixed in nickel microstructures was successively removed.

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Light output enhancement of a GaN-based light emitting diode by polymer film imprinting

Cited by 6 publications

References 21 publications

Demonstration of a simplified optical mouse lighting module by integrating the non-Lambertian LED chip and the free-form surface

Demonstration of a simplified optical mouse lighting module by integrating the non-Lambertian LED chip and the free-form surface

Integration of Non-Lambertian LED and Reflective Optical Element as Efficient Street Lamp

Dry etching of polydimethylsiloxane using microwave plasma

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