摘要
二维(2D)材料正被广泛用于宽带响应光电探测器(PD).然而,基于2D材料的宽带响应PD通常对红外波长的响应较差.在此,我们报告了垂直PtSe_(2)/超薄Al_(2)O_(3)/Ge PD在近红外照明下的优异光响应性能.我们直接硒化沉积在Al_(2)O_(3)/Ge上的Pt膜以形成PtSe_(2)层.超薄Al_(2)O_(3)钝化层起到表面改性的作用,有效地削弱了光生载流子的复合.在1550 nm的光照下,我们的PtSe_(2)/超薄Al_(2)O_(3)/Ge PD的工作面积为50μm×50μm,并在零偏压下获得了4.09 A W^(-1)、32.6/18.9μs的大响应度和快速上升/下降时间.在-5 V的外加电压下,PtSe_(2)/超薄Al_(2)O_(3)/Ge PD的响应度和响应速度分别高达38.18 A W^(-1)和9.6/7.7μs.我们发现器件的工作面积对光响应特性有很大的影响.此外,我们证明PtSe_(2)/超薄Al_(2)O_(3)/Ge PD阵列在室温下显示出了优异的紫外、可见光和红外成像能力.我们的研究表明,PtSe_(2)/超薄Al_(2)O_(3)/Ge异质结在设计具有优异近红外响应性能的新兴宽带光电子器件方面具有巨大的应用前景.
Two-dimensional(2D)materials are being intensively exploited for broadband-responsive photodetectors(PDs).However,the broadband-responsive PDs based on 2D materials normally suffer from poor response to infrared wavelengths.Here,we report the excellent photoresponse performance of vertical PtSe_(2)/ultrathin Al_(2)O_(3)/Ge PD under near-infrared illumination.We directly selenize Pt film deposited on Al_(2)O_(3)/Ge to form PtSe_(2)layer.The ultrathin Al_(2)O_(3)passivation layer plays the role of surface modification,effectively weakening recombination of the photogenerated carriers.Under 1550-nm illumination,the PtSe_(2)/ultrathin Al_(2)O_(3)/Ge PD with a working area of 50μm×50μm at zero bias obtains a large responsivity of 4.09 A W^(-1),and fast rise/fall times of 32.6/18.9μs,respectively.And under an external electric field of−5 V,the responsivity and response speed of the PtSe_(2)/ultrathin Al_(2)O_(3)/Ge PD can be as high as 38.18 A W^(-1)and as fast as 9.6/7.7μs,respectively.We find that the working area has a great influence on the photoresponse characteristics.Furthermore,we demonstrate the PtSe_(2)/ultrathin Al_(2)O_(3)/Ge PDs array shows outstanding violet,visible,and infrared imaging capability at room temperature.Our study suggests that the PtSe_(2)/ultrathin Al_(2)O_(3)/Ge heterojunction has great application prospects for the design of emerging broadband optoelectronic devices with superior performance for near-infrared response.
作者
朱清海
陈叶馨
朱笑东
孙一军
程志渊
徐敬
徐明生
Qinghai Zhu;Yexin Chen;Xiaodong Zhu;Yijun Sun;Zhiyuan Cheng;Jing Xu;Mingsheng Xu(School of Micro-Nano Electronics,State Key Laboratory of Silicon Materials,Zhejiang University,Hangzhou 310027,China;State Key Laboratory of Silicon Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China;College of Information Science&Electronic Engineering,Zhejiang University,Hangzhou 310027,China;Key Laboratory of Ocean Observation-Imaging Testbed of Zhejiang Province,Ocean College,Zhejiang University,Zhoushan 316021,China)
基金
supported by the National Natural Science Foundation of China(62090030/62090031,51872257,51672244,and 62274145)
the National Key R&D Program of China(2021YFA1200502)
the Natural Science Foundation of Zhejiang Province(LZ20F040001)
Zhejiang Province Key R&D programs(2020C01120)。
