Broadband Coherent Absorption in Chirped-Planar-Dielectric Cavities for 2D-Material-Based Photovoltaics and Photodetectors
Broadband Coherent Absorption in Chirped-Planar-Dielectric Cavities for 2D-Material-Based Photovoltaics and Photodetectors
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DOI：
10.1021/ph500107b
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发表时间：
2014-09
期刊：
影响因子：
7
通讯作者：
Jiabao Zheng;Robert A. Barton;D. Englund
中科院分区：
文献类型：
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作者：
Jiabao Zheng;Robert A. Barton;D. Englund
原子薄的材料，如石墨烯和过渡金属二硫属化物正在开发用于一系列光电器件，但它们的应用目前受到低光吸收的限制。在这里，我们描述了宽带相干吸收的啁啾布拉格反射器的介质腔设计。啁啾腔的吸收是由传输矩阵法计算和优化使用Nelder-Mead优化协议。我们数值模拟表明，与腔增强，单层二硫化钼光电探测器吸收高达33%的入射可见光超过300 nm的带宽，和原子薄单层石墨烯/单层二硫化钼太阳能电池的外量子效率可以提高3.6倍，预测值为7.09%。所提出的分层电介质结构在宽范围的入射角上工作，并且可以实现原子级薄光电探测器或太阳能电池的应用。
Atomically thin materials such as graphene and transition metal dichalcogenides are being developed for a range of optoelectronic devices, but their applications are currently limited by low light absorption. Here, we describe a dielectric cavity design with chirped Bragg reflectors for broadband coherent absorption. The chirped cavity absorption is calculated by the transfer matrix method and optimized using the Nelder–Mead optimization protocol. We numerically demonstrate that with cavity enhancement, a monolayer MoS2 photodetector absorbs as much as 33% of incident visible light over a 300 nm bandwidth, and the external quantum efficiency of an atomically thin monolayer graphene/monolayer MoS2 solar cell can be enhanced 3.6 times to a predicted value of 7.09%. The proposed layered dielectric structures operate across a wide range of incident angles and could enable applications for atomically thin photodetectors or solar cells.