Tunable structured AlGaN-based nanoporous distributed Bragg reflectors for light-coupling enhancement in monolayer MoS2
Tunable structured AlGaN-based nanoporous distributed Bragg reflectors for light-coupling enhancement in monolayer MoS2
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DOI：
10.1016/j.optlastec.2023.110508
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发表时间：
2023-12-23
影响因子：
5
通讯作者：
Dai，Jiangnan
中科院分区：
文献类型：
--
作者：
Tan，Shizhou;Jian，Pengcheng;Dai，Jiangnan
在这项工作中，我们展示了可调结构的AlGaN基纳米多孔（NP）分布式布拉格反射器（DBR）的高反射率，通过一步垂直-横向电化学蚀刻（ECE）。掺杂层中纳米孔的孔径以及NP-DBR表面V型坑的尺寸和密度可以通过控制刻蚀偏压来调节。此外，通过进一步调整交替层的厚度，我们实现了在从280到800 nm的波长范围内的多个中心波长的NP-DBR的高反射率。为了探索其潜在的应用，在NP-DBR上首次生长了具有红光区光致发光（PL）发射的MoS 2。由于表面V型凹坑的光局域效应和底部DBR的高反射率，MoS 2的光致发光强度比无NP-DBR的区域显著增强了37.3倍. MoS 2在多孔AlGaN和不同周期NP-DBR上的发光增强进一步验证了其发光增强机理。相应的理论模拟也表明，PL增强应归因于增强的光吸收和NP-DBR诱导的发射干涉的综合效应。AlGaN基NP-DBR的制备为提高二维层状材料的量子效率提供了一种新的途径，对于推动光电子领域小型化和集成化的2D/3D异质结构系统的发展具有重要意义。
In this work, we demonstrated tunable structured AlGaN-based nanoporous (NP) distributed Bragg reflectors (DBRs) with high-reflectivity through one-step vertical-lateral electrochemical etching (ECE). The aperture of nanopores in the doping layer and the size and density of V-pits on the surface of NP-DBRs can be tuned by controlling the etching bias. Furthermore, by further tuning the thickness of alternating layers, we achieved high reflectivity of NP-DBRs at multiple center wavelengths within the wavelength range from 280 to 800 nm. To explore its potential applications, MoS2with a photoluminescence (PL) emission in the red light region was grown for the first time on the NP-DBRs. Due to the light localized effect of surface V-pits and the high reflectivity of the bottom DBRs, the PL intensity of MoS2was significantly enhanced by a factor of 37.3 compared to the region without NP-DBRs. The PL enhancement of MoS2on porous AlGaN and different periodic NP-DBRs further validated the PL enhancement mechanism. The corresponding theoretical simulations also revealed that the PL enhancement should be attributed to the combined effect of enhanced light absorption and NP-DBRs induced emission interference. The fabricated AlGaN-based NP-DBRs provide a new approach for improving the quantum efficiency of two-dimensional layered materials, which holds significant importance for advancing the development of miniaturized and integrated 2D/3D heterogeneous structure systems in the field of optoelectronics.