Numerical study on optimization of active layer structures for GaN/AlGaN multiple-quantum-well laser diodes

Jun Rong Chen, Tsung-Shine Ko, Po Yuan Su, Tein Chang Lu, Hao Chung Kuo, Yen-Kuang Kuo, Shing Chung Wang

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21 Citations (Scopus)

Abstract

Theoretical analysis for different active layer structures is performed to minimize the laser threshold current of the ultraviolet GaN/AlGaN multiple-quantum-well laser diodes by using advanced device simulation. The simulation results show that the lower threshold current can be obtained when the number of quantum wells is two or three and the aluminum composition in the barrier layer is about 10%-12%. This result is attributed to several different effects including electron leakage current, nonuniform carrier distribution, interface charge density induced by spontaneous and piezoelectric polarization, and optical confinement factor. These internal physical mechanisms are investigated by theoretical calculation to analyze the effects of quantum-well number and different aluminum compositions in barrier layer on laser threshold properties. Furthermore, the effect of quantum-well thickness is discussed as well. It is found that the optimal quantum-well thickness is about 3 nm due to the balance of the advantages of a large confinement factor against the disadvantages of significant quantum-confined Stark effect (QCSE).

Original languageEnglish
Pages (from-to)3155-3165
Number of pages11
JournalJournal of Lightwave Technology
Volume26
Issue number17
DOIs
Publication statusPublished - 2008 Sep 1

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All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics

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