AlGaN UV Detector with Largely Enhanced Heat Dissipation on Mo Substrate Enabled by Van der Waals Epitaxy
AlGaN UV Detector with Largely Enhanced Heat Dissipation on Mo Substrate Enabled by Van der Waals Epitaxy
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通过范德华外延技术大幅增强 Mo 基板散热能力的 AlGaN 紫外探测器
DOI：
10.1021/acs.cgd.2c01273
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发表时间：
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影响因子：
3.8
通讯作者：
Dabing Li
中科院分区：
文献类型：
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作者：
Yang Chen;Hang Zang;Jianwei Ben;Shanli Zhang;Ke Jiang;Zhiming Shi;Yuping Jia;Mingrui Liu;Xiaojuan Sun;Dabing Li
金属衬底上的AlGaN外延具有许多优点，包括灵活性，垂直载流子注入和增强的光电器件散热；然而，由于传统外延技术存在严重的界面反应和晶格失配问题，对AlGaN的生长仍然存在许多挑战。在这项工作中，以石墨烯为插入层，通过范德华外延（vdWs）在多晶Mo衬底上生长定向AlGaN。采用高温退火AlN作为成核层，优化了后续AlGaN的结晶质量。石墨烯插入层的隔离效应产生了良好的外延界面，抑制了原子的扩散和化学反应，理论计算表明Al/Mo原子穿透石墨烯插入层的高能势垒。通过进一步生长n-AlGaN层作为光敏吸收剂制备紫外探测器，其响应率（1.7 × 10-3A W-1）可与传统蓝宝石相媲美。更好的是，Mo衬底上的UV探测器由于其较高的导热性而具有增强的散热能力，持续施加驱动电压后的温度升高大幅度降低了50%。本研究对利用vdWs外延技术在多晶金属衬底上生长AlGaN材料和制作大功率高压光电器件具有启发意义。
The epitaxy of AlGaN on metallic substrates exhibits numerous advantages including flexibility, vertical carrier injection, and enhanced heat dissipation for optoelectronic devices; however, there are still many challenges for the growth of AlGaN according to the serious interfacial reaction and lattice mismatch by conventional epitaxial techniques. In this work, thec-oriented AlGaN is grown on polycrystalline Mo substrate by van der Waals (vdWs) epitaxy with graphene as the insertion layer. A high-temperature annealed AlN is deposited as the nucleation layer, which optimizes the crystalline quality of following AlGaN. The isolation effect of the graphene insertion layer results in a good epitaxial interface, which suppresses the atoms diffusion and chemical reaction, demonstrating by the theoretical calculation of high energy barriers for Al/Mo atoms penetrating through graphene insertion layer. The ultraviolet (UV) detector is fabricated by further growing a n-AlGaN layer as the photosensitive absorber, whose responsivity (1.7 × 10–3A W–1) is comparable with that fabricated on conventional sapphire. Even better, the UV detector on the Mo substrate possesses enhanced heat dissipation ability due to its higher thermal conductivity, and the temperature elevation after consistently applying a drive voltage largely decreases by 50%. This work enlightens the growth of AlGaN materials and fabrication of high-power/high-voltage optoelectronic devices on polycrystalline metallic substrates by the mean of vdWs epitaxy.