Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland.
Nanoscale. 2019 Jan 31;11(5):2275-2281. doi: 10.1039/c8nr07065b.
While synthesis methods for pure ZnO nanostructures are well established, an efficient technique for the growth of ZnO-based nanowires or microrods that incorporate any type of quantum structure is yet to be established. Here, we report on the fabrication and optical properties of axial Zn1-xMgxO/ZnO/Zn1-xMgxO quantum wells that were deposited by molecular beam epitaxy on ZnO microrods obtained using a hydrothermal method. Using the emission energy results found in cathodoluminescence measurements and the results of a numerical modeling process, we found the quantum well width to be 4 nm, as intended, at the growth stage. The emission of quantum well-confined excitons persists up to room temperature. We used the fabricated structures to determine the carrier diffusion length (>280 nm) in ZnO using spatially resolved cathodoluminescence. The micro-photoluminescence results suggest an increase in the electron-phonon coupling strength with increasing microrod size.
虽然纯 ZnO 纳米结构的合成方法已经很成熟，但对于生长包含任何类型量子结构的 ZnO 基纳米线或微棒的有效技术仍有待建立。在这里，我们报告了通过分子束外延在水热法获得的 ZnO 微棒上沉积的轴向 Zn1-xMgxO/ZnO/Zn1-xMgxO 量子阱的制备和光学性质。使用在阴极发光测量中发现的发射能量结果和数值模拟过程的结果，我们发现量子阱宽度在生长阶段达到了预期的 4nm。量子阱限制激子的发射一直持续到室温。我们使用所制造的结构，通过空间分辨的阴极发光来确定 ZnO 中的载流子扩散长度（>280nm）。微光致发光结果表明，随着微棒尺寸的增加，电子-声子耦合强度增加。
