title: Midinfrared Photoluminescence up to 290 K Reveals Radiative Mechanisms and Substrate Doping-Type Effects of InAs Nanowires.
abstract: Photoluminescence (PL) as a conventional yet powerful optical spectroscopy may provide crucial insight into the mechanism of carrier recombination and bandedge structure in semiconductors. In this study, mid-infrared PL measurements on vertically aligned InAs nanowires (NWs) are realized for the first time in a wide temperature range of up to 290 K, by which the radiative recombinations are clarified in the NWs grown on n- and p-type Si substrates, respectively. A dominant PL feature is identified to be from the type-II optical transition across the interfaces between the zinc-blend (ZB) and the wurtzite (WZ) InAs, a lower-energy feature at low temperatures is ascribed to impurity-related transition, and a higher-energy feature at high temperatures originates in the interband transition of the WZ InAs being activated by thermal-induced electron transfer. The optical properties of the ZB-on-WZ and WZ-on-ZB interfaces are asymmetric, and stronger nonradiative recombination and weaker carrier-phonon interaction show up in the NWs on p-type substrate in which built-in electric field forms and leads to carrier assembling around the WZ-on-ZB interface. The results indicate that wide temperature-range infrared PL analysis can serve as efficient vehicle for clarifying optical properties and bandedge processes of the crystal-phase interfaces in vertically aligned InAs NWs.
authors.affiliation: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences , 200083 Shanghai, China.
authors.forename: Xiren
authors.identifier: 0000-0002-0527-1147
authors.initials: X
authors.lastname: Chen
authors.affiliation: Physics Department, Lancaster University , LA14YB Lancaster, United Kingdom.
authors.forename: Qiandong
authors.initials: Q
authors.lastname: Zhuang
authors.affiliation: Physics Department, Lancaster University , LA14YB Lancaster, United Kingdom.
authors.forename: H
authors.initials: H
authors.lastname: Alradhi
authors.affiliation: Physics Department, Lancaster University , LA14YB Lancaster, United Kingdom.
authors.forename: Zh M
authors.identifier: 0000-0001-5523-8153
authors.initials: ZM
authors.lastname: Jin
authors.affiliation: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences , 200083 Shanghai, China.|Key Laboratory of Polar Materials and Devices, East China Normal University , 200062 Shanghai, China.
authors.forename: Liangqing
authors.initials: L
authors.lastname: Zhu
authors.affiliation: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences , 200083 Shanghai, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.affiliation: National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences , 200083 Shanghai, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Shao
keywords: InAs nanowires; built-in electric field; infrared photoluminescence; nonradiative recombination; substrate