Thickness-dependent Raman spectra, transport properties and infrared photoresponse of few-layer black phosphorus
Thickness-dependent Raman spectra, transport properties and infrared photoresponse of few-layer black phosphorus
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DOI：
10.1039/c5tc01809a
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发表时间：
2015-10
影响因子：
6.4
通讯作者：
Sijie Liu;Nengjie Huo;Sheng Gan;Yan Li;Zhongming Wei;Beiju Huang;Jian Liu;Jingbo Li;Hongda Chen
中科院分区：
文献类型：
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作者：
Sijie Liu;Nengjie Huo;Sheng Gan;Yan Li;Zhongming Wei;Beiju Huang;Jian Liu;Jingbo Li;Hongda Chen
黑磷（BP）晶体薄层由于其可调的直接带隙、良好的物理性能以及在光电子学中的潜在应用而成为近年来新兴的一类二维（2D）材料。本文详细研究了BP多层膜的拉曼散射特性，包括A1 g、B2 g和A2 g模的频移和强度，发现它们与厚度和光偏振态有明显的依赖关系。研究了少层黑磷的光电性能，包括场效应特性和对不同波长激光的光敏性。薄膜的光电特性参数包括电流调制、迁移率、光响应率和响应时间等随薄膜厚度的变化而变化。在室温下，在较厚（15 nm）的BP器件中获得了明显的双极输运性质（空穴和电子迁移率分别高达240和2 cm 2 V-1 s-1），而较薄（9 nm）的BP仅显示P型输运。BP器件在不同激光照射下的光响应度达到几十mA W−1，这表明它们具有优异的光响应特性和宽带检测。较薄（9 nm）的BP在1550 nm的通信波段显示出64.8 mA W−1的高光响应度，这比较厚的样品大得多。我们的研究结果表明，BP的电荷传输和红外光响应性能是优异的，多样的，可以通过厚度控制有意识地设计。这些结果也表明BP在纳米电子器件和从可见光到通信波段（红外光）的光电探测方面的巨大潜力。
The crystalline thin layer of black phosphorus (BP) has emerged as a new category of two-dimensional (2D) materials very recently, due to its tunable direct bandgap, promising physical properties, and potential applications in optoelectronics. Herein, the Raman scattering properties of the few layers of BP including the frequency shift and the intensity of the A1g, B2g and A2g modes have been studied in detail and they show obvious dependence on thickness and light polarization. The optoelectronic performances of few-layer black phosphorus including field-effect properties and photosensitivity to laser light with different wavelengths are also investigated. The optoelectronic parameters including the current modulation, mobility, photoresponsivity and response time vary distinctly with the layer thickness. At room temperature, the obvious bipolar transport properties are obtained (with the hole and electron mobility as high as 240 and 2 cm2 V−1 s−1, respectively) in the thicker (15 nm) BP devices, while the thinner (9 nm) BP only shows P-type transportation. The photoresponsivity of BP devices under different laser light illumination reaches several tens of mA W−1, which demonstrates their excellent photo-responsive properties and broadband detection. The thinner (9 nm) BP shows a high photoresponsivity of 64.8 mA W−1 at the communication band of 1550 nm, which is much larger than that of the thicker sample. Our findings reveal that the charge transport and infrared photo-response properties of BP are excellent, and diverse and can be intentionally designed through the thickness control. Such results also suggest BP's great potential in nanoelectronic devices and photodetection from the visible light up to the communication band (infrared light).