Yazar "Liu, Jianxun" seçeneğine göre listele

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  • Küçük Resim Yok
    Öğe
    Influence of sidewall grating etching depth on GaN-based distributed feedback laser diodes
    (Iop Publishing Ltd, 2024) Feng, Meixin; Li, Chuanjie; Tang, Yongjun; Liu, Jianxun; Sun, Xiujian; Liu, Qifa; Yilmaz, Ercan
    Conventional sidewall gratings in GaN-based distributed feedback (DFB) laser diodes (LD) have a thick p-type layer, which may cause current spreading and carrier-induced anti-guiding effects, severely deteriorating the lasers performance. In this study, we report a novel fabrication technology to not only reduce the remaining p-type layer in the sidewall gratings but also realize close-coupled sidewall gratings. Afterwards, we further investigate the influence of the sidewall gratings etching depth on GaN-based DFB LDs. The results show an almost unchanged current injection efficiency, nearly coincided I-V curve and a near-field emission width for shallow etched structures, which indicate that the current spreading is neglectable in GaN-based ridge structure LDs. Based on this analysis, GaN-on-Si DFB LDs with an emission wavelength of 414 nm, full width at half maxima of 22 pm, and side mode suppression ratio of 19.1 dB were realized.
  • Küçük Resim
    Öğe
    Performance improvement of GaN-based microdisk lasers by using a PEALD-SiO2 passivation layer
    (Optica Publishing Group, 2023) Zhao, Hanru; Feng, Meixin; Liu, Jianxun; Sun, Xiujian; Li, Yongjian; Yılmaz, Ercan
    Dry-etching is often utilized to shape GaN-based materials. However, it inevitably causes plenty of sidewall defects as non-radiative recombination centers and charge traps that deteriorate GaN-based device performance. In this study, the effects of dielectric films deposited by plasma-enhanced atomic layer deposition (PEALD) and plasma-enhanced chemical vapor deposition (PECVD) on GaN-based microdisk laser performance were both investigated. The results demonstrated that the PEALD-SiO2 passivation layer largely reduced the trap-state density and increased the non-radiative recombination lifetime, thus leading to the significantly decreased threshold current, notably enhanced luminescence efficiency and smaller size dependence of GaN-based microdisk lasers as compared with the PECVD-Si3N4 passivation layer.