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Enhanced performance of nitride-based ultraviolet vertical-injection light-emitting diodes by non-insulation current blocking layer and textured surface.

Chiang YC, Lin BC, Chen KJ, Lin CC, Lee PT, Kuo HC - Nanoscale Res Lett (2014)

Bottom Line: For the purpose of light extraction and efficiency enhancement, the nitride-based ultraviolet vertical-injection light-emitting diodes (UV-VLEDs) with non-insulation current blocking layer (n-CBL) and optimized textured surface were fabricated.The optical and electrical characteristics were investigated in this n-CBL UV-VLED.Furthermore, the efficiency of optimized structure was improved by 5 ~ 6 times compared to our reference.

View Article: PubMed Central - PubMed

Affiliation: Institute of Lighting and Energy Photonics, National Chiao Tung University, No.301, Gaofa 3rd Rd., Guiren Dist., Tainan City, 71150, Taiwan, yenchih.chiang@gmail.com.

ABSTRACT
For the purpose of light extraction and efficiency enhancement, the nitride-based ultraviolet vertical-injection light-emitting diodes (UV-VLEDs) with non-insulation current blocking layer (n-CBL) and optimized textured surface were fabricated. The optical and electrical characteristics were investigated in this n-CBL UV-VLED. Furthermore, the efficiency of optimized structure was improved by 5 ~ 6 times compared to our reference.

No MeSH data available.


Related in: MedlinePlus

AFM images of emission area. (a) C-VLED after ICP 22-kÅ-deep dry etching, (b) UV-VLED-1 after ICP 5-kÅ-deep dry etching and KOH dipped for 120 s, (c) UV-VLED-2 after ICP 15-kÅ-deep dry etching and KOH dipped for 60 s, and (d) UV-VLED-3 after ICP 22-kÅ-deep dry etching.
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Fig3: AFM images of emission area. (a) C-VLED after ICP 22-kÅ-deep dry etching, (b) UV-VLED-1 after ICP 5-kÅ-deep dry etching and KOH dipped for 120 s, (c) UV-VLED-2 after ICP 15-kÅ-deep dry etching and KOH dipped for 60 s, and (d) UV-VLED-3 after ICP 22-kÅ-deep dry etching.

Mentions: Figures 2 and 3 present typical scanning electron microscope (SEM) and atomic force microscope (AFM) images of the etched n-GaN surface appearance for these UV-VLED samples. The insets in Figure 2 are the cross-sectional views of the etched surfaces. Among the n-CBL samples, different degrees of surface roughness are also fabricated to test their effects on output power. By varying the KOH etching time, three different degrees of surface morphology and surface roughness (Rms) can be achieved, as shown in Table 1. We noticed that the pyramid dimensions and pyramidal distribution density is inversely proportional with the etching time. With this result, we will find the relationship of luminous intensity and efficiency corresponds to different degrees of roughness.Figure 2


Enhanced performance of nitride-based ultraviolet vertical-injection light-emitting diodes by non-insulation current blocking layer and textured surface.

Chiang YC, Lin BC, Chen KJ, Lin CC, Lee PT, Kuo HC - Nanoscale Res Lett (2014)

AFM images of emission area. (a) C-VLED after ICP 22-kÅ-deep dry etching, (b) UV-VLED-1 after ICP 5-kÅ-deep dry etching and KOH dipped for 120 s, (c) UV-VLED-2 after ICP 15-kÅ-deep dry etching and KOH dipped for 60 s, and (d) UV-VLED-3 after ICP 22-kÅ-deep dry etching.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493838&req=5

Fig3: AFM images of emission area. (a) C-VLED after ICP 22-kÅ-deep dry etching, (b) UV-VLED-1 after ICP 5-kÅ-deep dry etching and KOH dipped for 120 s, (c) UV-VLED-2 after ICP 15-kÅ-deep dry etching and KOH dipped for 60 s, and (d) UV-VLED-3 after ICP 22-kÅ-deep dry etching.
Mentions: Figures 2 and 3 present typical scanning electron microscope (SEM) and atomic force microscope (AFM) images of the etched n-GaN surface appearance for these UV-VLED samples. The insets in Figure 2 are the cross-sectional views of the etched surfaces. Among the n-CBL samples, different degrees of surface roughness are also fabricated to test their effects on output power. By varying the KOH etching time, three different degrees of surface morphology and surface roughness (Rms) can be achieved, as shown in Table 1. We noticed that the pyramid dimensions and pyramidal distribution density is inversely proportional with the etching time. With this result, we will find the relationship of luminous intensity and efficiency corresponds to different degrees of roughness.Figure 2

Bottom Line: For the purpose of light extraction and efficiency enhancement, the nitride-based ultraviolet vertical-injection light-emitting diodes (UV-VLEDs) with non-insulation current blocking layer (n-CBL) and optimized textured surface were fabricated.The optical and electrical characteristics were investigated in this n-CBL UV-VLED.Furthermore, the efficiency of optimized structure was improved by 5 ~ 6 times compared to our reference.

View Article: PubMed Central - PubMed

Affiliation: Institute of Lighting and Energy Photonics, National Chiao Tung University, No.301, Gaofa 3rd Rd., Guiren Dist., Tainan City, 71150, Taiwan, yenchih.chiang@gmail.com.

ABSTRACT
For the purpose of light extraction and efficiency enhancement, the nitride-based ultraviolet vertical-injection light-emitting diodes (UV-VLEDs) with non-insulation current blocking layer (n-CBL) and optimized textured surface were fabricated. The optical and electrical characteristics were investigated in this n-CBL UV-VLED. Furthermore, the efficiency of optimized structure was improved by 5 ~ 6 times compared to our reference.

No MeSH data available.


Related in: MedlinePlus