Surface Transfer Doping-Induced, High-Performance Graphene/Silicon Schottky Junction-Based, Self-Powered Photodetector
Surface Transfer Doping-Induced, High-Performance Graphene/Silicon Schottky Junction-Based, Self-Powered Photodetector
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DOI：
10.1002/smll.201501298
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发表时间：
2015-10-07
期刊：
影响因子：
13.3
通讯作者：
Chen, Wei
中科院分区：
文献类型：
--
作者：
Xiang, Du;Han, Cheng;Chen, Wei
杜翔，程汉，胡泽华，伯雷，刘益阳，李旺，*文平虎，*和魏晨*由于器件耗尽区的局域扰动而受到限制。[8，9]基于光伏效应的自供电光电探测器可以在没有外部偏置的情况下工作。[3，10-12]由于自供电光电探测器中存在巨大的内置电势，光生电子-空穴对可以在零偏压下分离，从而有助于光导。[3]硅(Si)作为主要的半导体之一，已经被广泛地研究并应用于商业光伏器件中。由于其丰富的储量、高的光伏效率和成熟的加工技术。[13]大多数晶体硅基太阳能电池或自供电光电探测器都是以pn或pin结构制造的，这需要复杂而昂贵的离子注入(硼或磷)和扩散工艺来形成结。[13]为了降低制造成本并进一步提高其性能，探索新的器件结构具有重要意义。[14-16]与由pn或pin结组成的器件相比，基于肖特基结的硅器件通常是通过在硅片上沉积金属接触来构建的，显示出低成本和简单器件结构的优点。18.在电极/硅界面形成的肖特基结极大地促进了光生载流子在光照下的分离和传输过程。[19，20]然而，普通金属接触的透明度特别差，从而限制了基于肖特基结的硅光采集或探测器件的性能。[21，22]石墨烯是二维蜂窝结构中的单原子碳层，由于其极高的载流子迁移率(>；100000 cm 2V−1 S−1)，极低的方阻和优异的机械强度。[23-28]尤其是石墨烯，由于其高透射率和良好的导电性，在光伏器件中显示出巨大的潜在应用前景。[29-31]此外，石墨烯的电子性质和功函数可以很容易地被外部电场或化学掺杂调制，使得基于石墨烯的器件的性能非常可调。[32，33]因此，石墨烯被认为是一种很有前途的候选材料，可以作为肖特基结太阳能电池或自供电光电探测器的触点。Li等人。报道了第一个石墨烯/硅(Gr/Si)肖特基结
Du Xiang, Cheng Han, Zehua Hu, Bo Lei, Yiyang Liu, Li Wang,* Wen Ping Hu,* and Wei Chen* restricted due to the local perturbations within the device depletion regions.[8, 9] Self-powered photodetectors based on photovoltaic effect are able to be operated without external bias.[3, 10–12] Attributed to the large existing built-in electrical potential in self-powered photodetectors, the photogenerated electron–hole pairs can be separated at zero bias and thus contribute to the photoconduction.[3] Silicon (Si), as one of the leading semiconductors, has been extensively investigated and employed in commercial photovoltaic devices, owing to its abundant reserves, high photovoltaic efficiency, and mature processing technology.[13] Most of the crystalline Si based solar cells or self-powered photodetectors are fabricated as pn or pin structures, which requires sophisticated and costly ion injection (boron or phosphorus) and diffusion process to form the junctions.[13] In order to reduce the fabrication cost and further improve their performance, it is of great significance to explore novel device architectures.[14–16] Compared to the devices composed of pn or pin junctions, Schottky junctions based Si devices are normally constructed by depositing metal contacts on silicon wafers, showing the merits of low cost and simple device architecture.[17, 18] The Schottky junction formed at electrodes/Si interface strongly facilitates the separation and transport process of photocarriers upon light illumination.[19, 20] However, the transparency of common metal contacts is particularly poor, thus limiting the performance of Schottky junction based Si light harvesting or detecting devices.[21, 22] Graphene, a single atomic carbon layer in 2D honeycomb structures, has attracted tremendous research interests in carbon based electronics and optoelectronics, attributed to its extremely high charge carrier mobility (> 100 000 cm 2 V− 1 s− 1), low sheet resistance, and outstanding mechanical strengths.[23–28] In particular, graphene shows great potential applications as transparent conducting electrodes in photovoltaic devices resulting from its high transmittance for a wide spectrum and good electrical conductivity.[29–31] Moreover, the electronic properties and work function of graphene can be easily modulated by either external electrical field or chemical doping, making the performance of graphene-based devices quite tunable.[32, 33] As a result, graphene has been considered as a promising candidate to serve as contacts in Schottky junction based solar cells or self-powered photodetectors. Li et al. reported the first graphene/silicon (Gr/Si) Schottky junction based