Microscopy and biomimetics: the NanoSuit; method and image retrieval platform
Microscopy and biomimetics: the NanoSuit; method and image retrieval platform
复制标题
显微镜和仿生学：NanoSuit；
DOI：
10.1093/jmicro/dfu042
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发表时间：
2022
期刊：
影响因子：
1.8
通讯作者：
Hirasaka M
中科院分区：
文献类型：
--
作者：
Hariyama T;Takaku Y;Kawasaki H;Shimomura M;Senoh C;Yamahama Y;Hozumi A;Ito S;Matsuda N;Yamada S;Itoh T;Haseyama M;Ogawa T;Mori N;So S;Mitsuno H;Ohara M;Nomura S;Hirasaka M
包含精细纳米结构（例如量子点和量子威尔斯）的太阳能电池（SC）已经被严格地研究作为收获宽范围的太阳光谱的方式。然而，这些SC的能量转换效率仍然很低。为了进一步提高器件的性能，更深入地了解纳米结构在光伏转换过程中的作用是至关重要的，以获得有效的设计标准。为了实现这一点，局部电子特性，包括电势，能量状态，和周围的激发中心的电荷分布的特征在于在光照射下，因为它们管理的行为激发载流子。迄今为止，这些性质已间接推导出宏观表征，如电流-电压（I-V）测量;然而，它是不够的，以澄清相当复杂的纳米结构的作用。因此，需要以高空间分辨率直接测量这些特性，以了解光伏转换过程的详细机制。为此，我们一直在开发一个平台，用于在光照射条件下进行扫描隧道显微镜/光谱（STM/STS）、原子力显微镜（AFM）和开尔文探针力显微镜（KPFM）的工作。在这里，我们概述了基于III-V族化合物的多量子阱（QW）SC的表征，该多量子阱有望成为中间带型SC的潜在候选者。首先，我们给出了在空气中用KPFM测量SC的p-i-n结沿着的电势。在光照射条件下，在开路和短路配置中进行测量[图]。我们证明，可以成功地测量的开路电压对光的强度的依赖性通过仔细解释的KPFM数据。其次，我们介绍了利用双真空STM在原子尺度上表征多量子阱的一些例子，包括原子排列、电子态和能带分布。图1（a）KPFM在空气中的测量系统示意图。(b)光辐照对开路位形电位分布的影响。
Solar cells (SCs) that contain elaborate nanostructures, such as quantum dots and quantum wells, have been rigorously investigated as a way to harvest a wide range of the solar spectrum . However, the energy conversion efficiency of those SCs still remains low. For the further improvement of the device performance, a much deeper understanding of the role of nanostructures in the photovoltaic conversion process is essential to gain the effective design criteria. To achieve this, local electronic properties including electrical potential, energy states, and charge distribution around the excitation centers have to be characterized under light irradiation since they govern the behavior of excited carriers. These properties have so far been indirectly deduced from macroscopic characterization such as current-voltage (I-V) measurement; however, it is not sufficient to clarify rather complicated roles of the nanostructures . Thus, a direct measurement of those properties with high spatial resolution is required to understand the detailed mechanisms of the photovoltaic conversion process. To this end, we have been developing a platform for performing scanning tunneling microscopy/spectroscopy (STM/STS), atomic force microscopy (AFM), and Kelvin probe force microscopy (KPFM) working under light irradiation conditions.Here, we outline the characterization of a multiple quantum well (QW) SC based on III-V compounds that is expected to be a potential candidate of intermediate band type SC. First, we show the electrical potential measurements along thep-i-njunction of the SC using KPFM in air. Measurements were performed in open and short circuit configurations under light irradiation conditions [Fig.]. We demonstrate that the dependence of the open circuit voltage on the intensity of light can be successfully measured by careful interpretation of the KPFM data. Second, we introduce some examples of the atomic scale characterization of the multiple QW using ultrahigh vacuum STM including the atomic arrangement, electronic states, and band profile. Also, charge accumulation at the QW is discussed based on the topographic measurement under light irradiation.Fig. 1(a) Schematic illustration of measurement system of KPFM in air. (b) Effect of light irradiation on potential profile in open circuit configuration.