Charge transfer dynamics in Cu-doped ZnO nanowires

• Main Authors: Xing, Guozhong, Xing, Guichuan, Li, Mingjie, Sie, Edbert Jarvis, Wang, Dandan, Sulistio, Arief, Ye, Quan Lin, Huan, Alfred Cheng Hon, Wu, Tom, Sum, Tze Chien
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2011
• Subjects: DRNTU::Science::Chemistry::Physical chemistry
• Online Access: https://hdl.handle.net/10356/93831; http://hdl.handle.net/10220/6911
• Institution: Nanyang Technological University

Time resolved photoluminescence (TRPL) and transient absorption (TA) spectroscopy reveal an ultrafast charge transfer (CT) process, with an electron localization time constant 39+-9 ps, between the ZnO host and the Cu dopants in Cu-doped ZnO nanowires. This CT process effectively competes with the ZnO band edge emission, resulting in the quenching of the ZnO UV emission. TRPL measurements show that the UV decay dynamics coincides with the buildup of the Cu-related green emission. TA measurements probing the state-filling of the band edge and defect states provide further support to the CT model where the bleaching dynamics concur with the TRPL lifetimes.