Nanoengineered quantum dot medium for space optoelectronic devices
Nanoengineered quantum dot medium for space optoelectronic devices
复制标题
用于空间光电器件的纳米工程量子点介质
作者：
S. Oktyabrsky;V. Tokranov;M. Yakimov;A. Sergeev;V. Mitin
在纳米系统中，通过控制载流子动力学可以提高空间光电子器件的耐温性和抗电离辐射性能。讨论了与光子应用相关的自组装异质外延InAs量子点(QD)介质的最新科学技术成果。重点放在通过分子束外延对量子点进行建模和受控制造的量子点系综中电子光谱和电势分布的纳米工程来管理载流子动力学。形状工程的量子盘片被嵌入到GaAs量子阱中，可以承受比量子阱高两个数量级的质子剂量，并解释了高发光效率和热稳定的激光二极管。量子点中的内置电荷不仅起到改善近红外和中红外光吸收的作用，而且还控制着结构中的光电子寿命。带负电荷的量子点介质是最近显示太阳能电池效率得到可信改善的第一种量子点材料。这是红外能量捕获和抑制快速电子捕获过程的结果。因此，预计量子化InAs/GaAs光伏将克服多结太阳能电池的效率和寿命。量子点内置电荷的电势也是提高量子点红外探测器光电子寿命的原因。量子点相关团簇在团簇周围提供了更高的集体势垒，构成了一种新的方法，它结合了可管理的光电子寿命、高迁移率和可调谐的局域态和导电态。
Resistance to temperature and ionizing radiation of space optoelectronic devices can be improved through control of carrier kinetics in nanoscale systems. Recent results in the science and technology of self-assembled heteroepitaxial InAs quantum dot (QD) medium related to photonic applications are discussed. Focus is placed on management of carrier kinetics via nanoengineering of electronic spectrum and potential profiles in the QD ensemble using modeling and controlled fabrication of QDs with molecular beam epitaxy. Shape-engineered QD sheets embedded into GaAs quantum wells were found to withstand two orders of magnitude higher proton dose than QWs and to account for high luminescence efficiency and thermally stable laser diodes. Built-in charge in QDs is responsible for improvement of both near and mid-IR optical absorption, but also control photoelectron lifetime in the structures. The negatively charged QD medium was the first QD material that has recently shown credible improvement of solar cell efficiency. It has resulted from IR energy harvesting and suppressed fast electron capture processes. It is thus expected that QD InAs/GaAs photovoltaics will overcome the efficiency and lifespan of multi-junction solar cells. Potentials due to QD built-in charge are also responsible for improved photoelectron lifetime in QD infrared photodetectors. QD correlated clusters provide even higher collective potential barriers around clusters and constitute the novel approach to the optoelectronic materials combining manageable photoelectron lifetime, high mobility, and tunable localized and conducting states.