Temperature-dependent photoluminescence analysis of ZnO nanowire array annealed in air. (May 2018)

• Record Type: Journal Article
• Authors: Sun, Yanan; Gu, Xiuquan; Zhao, Yulong; Wang, Linmeng; Qiang, Yinghuai
• Is Part Of: Superlattices and microstructures. Volume 117(2018)
• Page Start: 520
• Page End: 526
• Publication Date: 2018-05
• Subjects: ZnO -- Photoluminescence -- Nanowire -- Array -- Exciton -- Annealing; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2018.03.083
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: ZnO nanowire arrays (NWAs) were prepared on transparent conducting fluorine doped tin oxide (FTO) substrates through a facile hydrothermal method, followed by a 500 °C annealing to improve their crystalline qualities and photoelectrochemical (PEC) activities. It was found that the annealing didn't change the morphology, but resulted in a significant reduction of the donor concentration. Temperature-dependent photoluminescence (PL) was carried out for a comprehensive analysis of the effect from annealing. Noteworthy, four dominant peaks were identified from the 10 K spectrum of a 500 °C annealed sample, and they were assigned to FX, D 0 X, (e, D 0 ) and (e, D 0 ) -1LO, respectively. Of them, the FX emission was only existed below 130 K, while the room-temperature (RT) PL spectrum was dominated by the D 0 X emission. Highlights: ZnO nanowire arrays were prepared on the transparent conducting substrates via a hydrothermal method. A comparison was made on the low-temperature PL spectra of ZnO nanowire arrays before and after annealing. Free exciton emission was identified from the spectra of the annealed ZnO sample. Near band edge emission of the annealed ZnO sample was dominated by neutral-donor bound excitons (D 0 X) at room temperature.