Epitaxial Growth of InGaN Nanowire Arrays for Light Emitting Diodes

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• 作者：Christopher Hahn ; Zhaoyu Zhang ; Anthony Fu ; Cheng Hao Wu ; Yun Jeong Hwang ; Daniel J. Gargas ; Peidong Yang
• 刊名：ACS Nano
• 出版年：2011
• 出版时间：May 24, 2011
• 年：2011
• 卷：5
• 期：5
• 页码：3970-3976
• 全文大小：1013K
• 年卷期：0
• ISSN：1936-086X

文摘

Significant synthetic challenges remain for the epitaxial growth of high-quality InGaN across the entire compositional range. One strategy to address these challenges has been to use the nanowire geometry because of its strain relieving properties. Here, we demonstrate the heteroepitaxial growth of In_xGa_1–xN nanowire arrays (0.06 ≤ x ≤ 0.43) on c-plane sapphire (Al₂O₃(001)) using a halide chemical vapor deposition (HCVD) technique. Scanning electron microscopy and X-ray diffraction characterization confirmed the long-range order and epitaxy of vertically oriented nanowires. Structural characterization by transmission electron microscopy showed that single crystalline nanowires were grown in the ⟨002⟩ direction. Optical properties of InGaN nanowire arrays were investigated by absorption and photoluminescence measurements. These measurements show the tunable direct band gap properties of InGaN nanowires into the yellow-orange region of the visible spectrum. To demonstrate the utility of our HCVD method for implementation into devices, LEDs were fabricated from In_xGa_1–xN nanowires epitaxially grown on p-GaN(001). Devices showed blue (x = 0.06), green (x = 0.28), and orange (x = 0.43) electroluminescence, demonstrating electrically driven color tunable emission from this p–n junction.