Coaxial silicon nanowires as solar cells and nanoelectronic power sources
Coaxial silicon nanowires as solar cells and nanoelectronic power sources
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DOI：
10.1038/nature06181
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发表时间：
2007-10-18
期刊：
影响因子：
64.8
通讯作者：
Lieber, Charles M.
中科院分区：
文献类型：
--
作者：
Tian, Bozhi;Zheng, Xiaolin;Lieber, Charles M.
太阳能电池是清洁和可再生能源的有吸引力的候选者（1，2）;随着小型化，它们也可能作为纳米电子系统的集成电源。纳米结构或纳米结构材料的使用代表了降低成本和尺寸以及提高光化学效率的一般方法（1-9）。纳米颗粒、纳米棒和纳米线已被用于提高聚合物共混物（4）和染料敏化太阳能电池（5，6）中的电荷收集效率，以证明载流子倍增（7），并能够实现光伏器件的低温加工（3-6）。此外，最近的理论研究表明，相对于相同材料的单晶体半导体，同轴纳米线结构可以改善载流子收集和整体效率（8，9）。然而，基于混合纳米架构的太阳能电池具有相对低的效率和差的稳定性（1）。此外，以前的研究还没有解决它们作为纳米电子学中的光伏功率元件的用途。在这里，我们报告的p型/本征/n型（p-i-n）同轴硅纳米线太阳能电池的实现。在一个太阳当量（1个太阳）照明下，p-i-n硅纳米线元件每个纳米线器件的最大功率输出高达200 pW，表观能量转换效率高达3.4%，在高通量照明下可实现稳定和改进的效率。此外，我们表明，个别和互连的硅纳米线光伏元件可以作为强大的电源驱动功能的纳米电子传感器和逻辑门。这些同轴硅纳米线光伏元件为光致能量/电荷传输和人工光合作用的研究提供了一个新的纳米级测试平台（10），并且可能会发现作为超低功率电子器件（11）和各种纳米系统（12，13）供电的元件的一般用途。
Solar cells are attractive candidates for clean and renewable power(1,2); with miniaturization, they might also serve as integrated power sources for nanoelectronic systems. The use of nanostructures or nanostructured materials represents a general approach to reduce both cost and size and to improve efficiency in photovoltaics(1-9). Nanoparticles, nanorods and nanowires have been used to improve charge collection efficiency in polymer-blend(4) and dye-sensitized solar cells(5,6), to demonstrate carrier multiplication(7), and to enable low-temperature processing of photovoltaic devices(3-6). Moreover, recent theoretical studies have indicated that coaxial nanowire structures could improve carrier collection and overall efficiency with respect to single-crystal bulk semiconductors of the same materials(8,9). However, solar cells based on hybrid nanoarchitectures suffer from relatively low efficiencies and poor stabilities(1). In addition, previous studies have not yet addressed their use as photovoltaic power elements in nanoelectronics. Here we report the realization of p-type/intrinsic/n-type (p-i-n) coaxial silicon nanowire solar cells. Under one solar equivalent (1-sun) illumination, the p-i-n silicon nanowire elements yield a maximum power output of up to 200 pW per nanowire device and an apparent energy conversion efficiency of up to 3.4 per cent, with stable and improved efficiencies achievable at high-flux illuminations. Furthermore, we show that individual and interconnected silicon nanowire photovoltaic elements can serve as robust power sources to drive functional nanoelectronic sensors and logic gates. These coaxial silicon nanowire photovoltaic elements provide a new nanoscale test bed for studies of photoinduced energy/charge transport and artificial photosynthesis(10), and might find general usage as elements for powering ultralow-power electronics(11) and diverse nanosystems(12,13).