Room-temperature photoluminescence from ZnO∕ZnMgO multiple quantum wells grown on Si(111) substrates

Abstract

A set of ten-period ZnO∕Zn0.85Mg0.15O multiple quantum wells with well thickness varying from 2.5to5nm has been grown on Si(111) substrates by pulsed laser deposition. A periodic structure with sharp interfaces was observed by cross-sectional transmission electron microscopy. The room-temperature photoluminescence resulting from the well regions exhibits a significant blueshift with respect to the ZnO single layer. The well layer thickness dependence of the emission energy from the well regions was investigated and compared with a simple theoretical model. The results suggest that the quantum confinement effects in the quantum wells can be observed up to room temperature.

Optical properties of homo- and heteroepitaxial single quantum wells grown by pulsed-laser deposition

“…Misra et al grew ZnO=Mg 0:34 Zn 0:66 O QWs by pulsed-laser deposition (PLD) on c-plane sapphire substrates [8] and reported room-temperature luminescence from the quantum wells. Gu et al presented the growth of MQWs by PLD on Si(1 1 1) [9], obtaining sharp interfaces and room temperature PL from the quantum well.…”

Comparison of structural and optical properties of polar and non-polar ZnO/Zn0.9Mg0.1O MQWs fabricated on sapphire substrates by pulsed laser deposition

“…By taking the advantage of multiple quantum wells (MQWs) structures such as ZnO/ZnMgO or ZnO/ZnCdO MQWs, more stable and efficient as well as lower threshold UV electroluminescence (EL) emission can be achieved [4]. So far, much effort has been devoted toward the investigation and fabrication of ZnO/ZnMgO MQWs for UV light emitter applications [5][6][7][8]. However, most of these samples were grown along the polar c-axis direction.…”

Structure and optical properties of multi-quantum wells grown on Si(111) substrates

“…Recently, most researches have focused on the investigation and fabrication of ZnO/ZnMgO MQWs because of the similar radius of Mg 2+ (0.57 Å) and Zn 2+ (0.60 Å) [11][12][13][14][15]. In our previous studies, ZnO-related MQW structures were fabricated successfully on Si(111) substrates by PLD [16,17]. Low-temperature photoluminescence (PL) spectroscopy is a very helpful tool for studying the excitonic behavior of the MQWs structures.…”

“…In this work, we focus on the temperature-dependent PL measurements of ZnO MQWs to reveal the effects of the well thickness and barrier composition on the optical properties. [16]. The buffer layers were 50 nm thick for all the samples, while the compositions were the same as those of the barrier layer materials.…”