Unique photoluminescence from ZnO grown by eclipse pulsed laser deposition

作者：Mendel**erg R J^*; Kennedy J V; Durbin S M; Reeves R J

来源：JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B, 2009, 27(3): 1698-1704.

DOI：10.1116/1.3137968

• excitons
• II-VI semiconductors
• ion implantation
• lead
• nanostructured materials
• photoluminescence
• polaritons
• pulsed laser deposition
• semiconductor doping
• wide band gap semiconductors
• zinc compounds

Nanostructured ZnO was deposited by eclipse pulsed laser deposition from a metallic Zn target in an oxygen atmosphere. Photoluminescence (PL) was carried out on the structures at liquid helium temperatures. The temperature dependence of the PL as well as the power dependence at 4 K gave insight into the processes governing the light emission from these samples. Free A and B excitonic emission was observed as well as exciton-polariton emission from the upper and lower polariton branches. The low temperature PL was dominated by the I(7) exciton, which currently has an unknown chemical origin and is not commonly observed in the PL spectrum of bulk ZnO. Power dependence of the I(7) feature showed unique behavior not previously reported. All the other features had nearly linear power dependence while the I(7) peak had an emission exponent of 1.53 +/- 0.01. Lead was the dominant impurity in the Zn target used to grow the eclipse pulsed laser deposited (EPLD) samples and seemed a likely candidate for the origin of the I(7) excitonic peak. Implantation of Pb into bulk ZnO showed no appearance of the I(7) feature at 0.01% Pb concentration. As such, Pb may not be the origin of the I(7) feature which dominates the PL from the EPLD grown samples. However, due to the complicated interactions of Pb in a ZnO host, it is likely that the Pb is incorporated differently in the implanted bulk and EPLD grown ZnO.

• 出版日期2009-5