基于碳纳米薄膜/砷化镓范德华异质结的高性能自驱动光电探测器研究

基于碳纳米材料/体半导体范德华(vdW)异质结的光电器件可以同时实现碳纳米材料的超高载流子迁移率以及体半导体的优异光电性能,且具有结构简单、工艺简便、易于调控界面等优点。尤其是通过调控单壁碳纳米管(SWCNT)的直径/手性、费米能级等可以与体半导体形成能带匹配、具有原子级界面的新型混合维度vdW异质结。本文报道了一种基于(6,5)手性为主的SWCNT薄膜与n型GaAs所形成的pn结的宽光谱自驱动光电探测器,并利用石墨烯降低SWCNT薄膜内载流子的复合几率和促进载流子传输。实验结果表明,器件对405~1064 nm波段光子表现出高灵敏的光电响应,零偏压条件下最大光电响应度和比探测率分别可达1.214 A/W和2×10¹² Jones。

High-performance self-powered photodetectors based on the carbon nanomaterial/GaAs vdW heterojunctions

With the advantages such as simple structure,simple process and easy interface control,the photoelectric devices based on carbon nanomaterial/bulk semiconductor van der Waals(vdW)heterojunctions can fully realize the ultrahigh carrier mobility of carbon nanomaterials and the excellent photoelectric properties of bulk semiconductors.Especially,the novel mixed-dimensional vdW heterojunctions can be prepared by controlling the diameter/chirality and Fermi level of single-walled carbon nanotubes(SWCNTs)to form atomic-level interfaces and match bandgaps with bulk semiconductors.Here,we reported a self-powered broadband photodetector based on the pn vdW heterojunctions by combining(6,5)-enriched semiconducting SWCNT film with n-type GaAs,and used graphene to reduce the probability of carrier recombination in SWCNT film and to promote the carrier transport.The experimental results suggest that the self-powered device exhibits high-sensitivity photoelectric response toward the incident photons in the 405~1064 nm range,and that the max photoelectric responsivity of 1.214 A/W and the specific detectivity of 2×10¹² Jones could be achieved at zero bias.