Structural and optical investigations of periodically polarity inverted ZnO heterostructures on (0001) Al2O3

Abstract

We report the structural and optical properties of one-dimensional grating of ZnO consisting of periodically polarity inverted structures on (0001) Al2O3 substrates. The inversion domain boundaries (IDBs) between the Zn- and the O-polar ZnO regions were clearly observed by transmission electronic microscopy. The investigation of spatially resolved local photoluminescence (PL) revealed strong excitonic emission at the interfacial region including the IDBs. The possible mechanism of strong PL has been discussed by the consideration of atomic configuration and carrier collection including its lifetime and diffusion process in Zn- and O-polar regions. Therefore the authors conclude that the IDBs can be active for the strong emission not a nonradiative center.

Polarity continuation and frustration in ZnSe nanospirals

“…On the other hand, the reversal of polarity across interfaces is also possible in various semiconductors. The periodically polarity-inverted ZnO heterostructures on (0001) Al 2 O 3 reveal strong exitonic emission at the interface region 12 . Polarity inversion of GaN is realized by deposition and patterning of a thin low-temperature AlN nucleation layer 13 .…”

Anisotropic properties of periodically polarity-inverted zinc oxide structures

“…7͑a͒. Park et al 24 reported the inversion domain boundary formation between both polar region in similar structured PPI ZnO structures. In this time, we want to focus on the transition regions to find out the origin of anisotropic broadening of FWHM of ZnO ͑0002͒.…”

Growth and characterization of periodically polarity-inverted ZnO structures on sapphire substrates

“…6 shows temperature dependent PL spectra obtained from PPI ZnO structures with 500 nm period. Before the temperature variation, the m-PL spectra obtained from both polar region and interface region between Zn-and O-polar at 77 K. The interface region shows the highest PL intensity among measured regions which is related to the physical geometry or diffusion length difference depending on Zn-and O-polar regions [8].…”

“…4(a). The detailed interfacial properties between Zn-and O-polar regions can be found in elsewhere [8].…”

“…To date, however, only a few results have been reported on the fabrication of periodically polarity changed ZnO structures on sapphire substrates [7,8]. It was be so, but the optical and structural study on the PPI ZnO structures is considered as an indispensable step toward the various applications such as electronic, optoelectronic, electrochemical, and electromechanical devices [9,10].…”