Al:ZnO as a platform for near-zero-index photonics: enhancing the doping efficiency of atomic layer deposition
Al:ZnO as a platform for near-zero-index photonics: enhancing the doping efficiency of atomic layer deposition
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DOI：
10.1364/ome.409347
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发表时间：
2020-12-01
影响因子：
2.8
通讯作者：
Kinsey, N.
中科院分区：
文献类型：
--
作者：
Fomra, D.;Ding, K.;Kinsey, N.
主要的技术突破通常是由材料研究的进步驱动的，光学技术也没有什么不同。在过去的几年中，由于其光学特性的出色可调节性和增强的光 - 物质相互作用，接近零索引（NZI）的材料引起了重大兴趣，从而导致了几次紧凑，能效和动态的纳米光子设备的证明。这些设备中的许多设备都依赖于透明的导电氧化物（TCO）作为动态层，因为这些材料在电信波长时表现出接近零索引。在用于沉积TCO的广泛技术中，原子层沉积（ALD）提供了保质性，可伸缩性和低底物温度等优点。但是，由于高（> 10（20）CM（-3））掺杂水平的掺杂效率低，因此ALD过程通常会导致光学质量较差的膜。在这项工作中，我们展示了一个修改后的ALD过程，以存入TCO，以Al：Zno为例，这导致掺杂效率从13％提高到54％。修改后的ALD过程远离掺杂剂（铝）前体的表面饱和度，在整个薄膜中导致掺杂剂（AL）的分布更加均匀，产生高电导率（2.8x10（-4）欧米茄-CM）偶氮膜，其交叉波长在sapphire和silicon siperical syical subsical subsical complates and sapphire subsical subsical subsical complate syical siperication sycortillaties complate syclate syclate sycornation complate consiCOnters s sappherates sycornaties complates incortial and cossoter。 （c）2020年美国光学学会根据OSA开放访问发布协议条款
Major technological breakthroughs are often driven by advancements in materials research, and optics is no different. Over the last few years, near-zero-index (NZI) materials have triggered significant interest owing to their exceptional tunability of optical properties and enhanced light-matter interaction, leading to several demonstrations of compact, energy-efficient, and dynamic nanophotonic devices. Many of these devices have relied on transparent conducting oxides (TCOs) as a dynamic layer, as these materials exhibit a near-zero-index at telecommunication wavelengths. Among a wide range of techniques employed for the deposition of TCOs, atomic layer deposition (ALD) offers advantages such as conformality, scalability, and low substrate temperature. However, the ALD process often results in films with poor optical quality, due to low doping efficiencies at high (>10(20)cm(-3)) doping levels. In this work, we demonstrate a modified ALD process to deposit TCOs, taking Al:ZnO as an example, which results in an increase in doping efficiency from 13% to 54%. Moving away from surface saturation for the dopant (aluminum) precursor, the modified ALD process results in a more uniform distribution of dopants (Al) throughout the film, yielding highly conductive (2.8x10(-4) Omega-cm) AZO films with crossover wavelengths as low as 1320nm and 1370nm on sapphire and silicon substrates, respectively. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement