Research on vertical-type large-area high-power deep-UV LEDs fabricated on Si substrates

2014 Fiscal Year Final Research Report

• Project/Area Number: 24246010
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Applied materials science/Crystal engineering
• Research Institution: The Institute of Physical and Chemical Research
• Principal Investigator: HIRAYAMA Hideki 独立行政法人理化学研究所, 平山量子光素子研究室, 主任研究員 (70270593)
• Co-Investigator(Kenkyū-buntansha): FUJIKAWA Sachie 理化学研究所, 平山量子光素子研究室, 研究員 (90550327)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 深紫外LED / AlGaN / AlN / MOCVD / Si基板 / 縦型LED / 光取りだし効率 / 内部量子効率

Outline of Final Research Achievements

The development of high-power deep-ultraviolet light-emitting diodes (DUV-LEDs) is quite an important subject because they are required for a wide variety of applications, such as sterilization, water purification, medicine and biochemistry. However, high-power operation of a DUV-LED fabricated on a sapphire substrate is difficult because of a large series resistance due to a lateral-injection and a low light-extraction efficiency (LEE). The purpose of this work is to realize a high-power DUV-LED by fabricating a vertical-type large-area LED device on a silicon (Si) substrate.
We demonstrated high-quality AlN buffer layers with no surface cracks by fabricating them on patterned Si substrates. We obtained milli-watt power operations of DUV-LEDs fabricating on the high-quality AlN layer grown on the patterned substrates. We also achieved significant increase of LEE of DUV LED by introducing a transparent p-type AlGaN contact layer and a highly-reflective electrode.

Free Research Field

量子電子・光デバイス工学　半導体工学