Zn and ZnO nanoparticles fabricated by ion implantation combined with thermal oxidation, and the defect-free luminescence

Abstract

Silica glass implanted with Zn ions of 60keV to 1.0×1017ions∕cm2 was annealed in oxygen gas to form ZnO nanoparticles (NPs). In as-implanted state, the implanted Zn atoms form Zn metallic NPs inside of the silica. After annealing at 600°C, ZnO NPs form on the surface, while Zn metallic NPs still remain in the deep region. At 700°C, most of Zn atoms move to the surface to form the droplet-shaped ZnO NPs which show two photoluminescence bands, i.e., an exciton band at 375nm and a defect band at ∼500nm. The defect band almost disappears in the samples annealed at 600°C, which include both ZnO NPs and Zn NPs.

Room-temperature single-photon emission from zinc oxide nanoparticle defects and their in vitro photostable intrinsic fluorescence

“…In this paper, we present single-photon emission from defects in ZnO NPs formed by Zn ion implantation followed by thermal oxidation [42,43,50]. We observe red defect emissions under 532 nm excitation at room temperature, where the defects exhibit blinking characteristics with occasional photostability.…”

“…Single-photon emission was overlooked for decades because material scientists generally perform ensemble (i.e. bulk) measurements [42,43], which end up sampling multiple optical defects. A thorough knowledge of the growth conditions and introduced defects coupled with high-resolution fluorescence microscopy, alongside density functional theory calculations, can yield the correct chemical origin of the defects.…”

Optical emission and absorption spectra of Zn–ZnO core-shell nanostructures

“…The presence of metallic Zn in the structure is evident from the GIXRD diffraction pattern. There is no signature corresponding to absorption peak due to surface plasmon resonance effect [22,23] for Zn metal nanoparticles (due to coulombic interaction by dielectric screening). Usually, excess carriers donated by impurities (blue shift of optical band-to-band transitions) lead to Burstein-Moss (BM) effect [24].…”

Electronic structure and photoluminescence properties of Zn-ion implanted silica glass before and after thermal annealing

“…It is not surprising, because the understanding of Zn-ion incorporation process is the point for controlled modification of key electronic properties for SiO 2 :Zn system that might be employed in the fields of photovoltaics, light-emitting/laser applications, optoelectronics, etc. An accumulated data reported previously [2][3][4][5][6][7][8] allow to conclude that most of technologists are using thermal annealing in the range of temperatures from 600 o C up to 700 o C after Zn-ion embedding process in order to obtain the defect-free high-quality Zn-doped SiO 2 . But these recent results seem far away from being perfect -i.e.…”

“…[4][5][6][7][8]). It is not surprising, because the understanding of Zn-ion incorporation process is the point for controlled modification of key electronic properties for SiO 2 :Zn system that might be employed in the fields of photovoltaics, light-emitting/laser applications, optoelectronics, etc.…”