Investigation of Micromorphology and Carrier Recombination Dynamics for InGaN/GaN Multi-Quantum Dots Grown by Molecular Beam Epitaxy

oleh: Xue Zhang, Wenxian Yang, Zhiwei Xing, Haibing Qiu, Ying Gu, Lifeng Bian, Shulong Lu, Hua Qin, Yong Cai, Yuta Suzuki, Sakuya Kaneko, Yuki Matsuda, Shinji Izumi, Yuichi Nakamura, Atsushi Tackeuchi

Format: Article
Diterbitkan: MDPI AG 2021-10-01

Deskripsi

InGaN quantum dots (QDs) are promising candidates for GaN-based all-visible optoelectronic devices such as micro light-emitting diode and laser. In this study, self-assembled InGaN/GaN multi-quantum dots (MQDs) have been grown by plasma-assisted molecular beam epitaxy on c-plane GaN-on-sapphire template. A high density of over 3.8 × 10<sup>10</sup> cm<sup>−2</sup> is achieved and InGaN QDs exhibit a relatively uniform size distribution and good dispersity. Strong localization effect in as-grown InGaN QDs has been evidenced by temperature-dependent photoluminescence (PL). The variation of peak energy is as small as 35 meV with increasing temperature from 10 K to 300 K, implying excellent temperature stability of emission wavelength for InGaN MQDs. Moreover, the radiative and nonradiative recombination times were calculated by time-resolved PL (TRPL) measurements, and the temperature dependence of PL decay times reveal that radiative recombination dominates the recombination process due to the low dislocation density of QDs structure.