Characterization and Fabrication of InGaN-based Blue LED with Underlying AlGaN/GaN SLS Cladding Layer Grown on Si(111) S
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1167-O04-01
Characterization and Fabrication of InGaN-based blue LED with Underlying AlGaN/GaN SLS Cladding Layer Grown on Si(111) Substrate Bin Abu Bakar Ahmad Shuhaimi1,2,*, Pum Chian Khai1,2, Takaaki Suzue1,2, Yukiyasu Nomura1,2 and Takashi Egawa1,2 1 Research Center for Nano-Device and System, Nagoya Institute of Technology, Nagoya, Japan. 2 Graduate School of Engineering Physics, Electronics and Mechanics, Nagoya Institute of Technology, Nagoya, Japan.
ABSTRACT This paper reports improved optical characteristics of InGaN-based light-emitting-diode (LED) grown on Si(111) substrate by the insertion of an Al0.06Ga0.94N/GaN strained-layersuperlattices (SLS) cladding layer after AlN/GaN multilayer (ML) growth, under the multiquantum-well (MQW) active layer. The insertion of underlying Al0.06Ga0.94N/GaN SLS cladding layer has shown to improve epitaxial layer quality in x-ray diffraction (XRD) analysis, reduce wavelength peak fluctuations in photoluminescence (PL) surface mapping, and improve optical and electrical characteristics of the LED sample. A 34% increase of light intensity at 50 mA current injection and a narrower wavelength peak have been achieved by the insertion of Al0.06Ga0.94N/GaN SLS cladding layer. LED with underlying Al0.06Ga0.94N/GaN also shows superior current-voltage (I-V) characteristics with operation voltage of 3.2 V at 20 mA and series resistance of 16 Ω. INTRODUCTION Si(111) is a very promising substrate for the growth of low-cost GaN-based energysaving light-emitting devices with wavelength ranging from ultra-violet to infrared illumination. However, large thermal mismatch of 116% and lattice mismatch of 17% between GaN epitaxial layer and the Si(111) substrate contributes to low-quality film with threading dislocation density (TDD) of approximately larger than ~ 1010 (cm -2 ) in conventional metal organic chemical vapor deposition (MOCVD) growth method [1]. The smaller band-gap of Si substrate compared to the band-gap of InGaN-based active layer in visible light-emitting devices structure attributes to the absorption of emitted light by the substrate, causing poor light emission from the device. Ishikawa et al. has reported an improved light output power for light-emitting diode (LED) grown in Si(111) substrate using an Al0.3Ga0.7N/AlN distributed Bragg reflector (DBR) to reduce the optical loss [2]. However, the pair number is limited to 5 to obtain a crack-free film. Recently, we have reported reduction of TDD and enhancement of internal quantum efficiency in InGaNbased multi-quantum-well with the insertion of Al0.06Ga0.94N/GaN SLS cladding layer under the active layer [3]. The Al0.06Ga0.94N/GaN SLS cladding layer can also be used to reduce optical loss to the substrate in LED operation. In this paper, we report material characterization and fabrication of InGaN-based blue LED with underlying Al0.06Ga0.94N/GaN SLS cladding layer ____________________________________ * Corresponding author, e-mail: [email protected]
grown on Si(111) substrate. This paper is intended to demonstrate the su
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