Recombination dynamics in aerotaxy-grown Zn-doped GaAs nanowires
Recombination dynamics in aerotaxy-grown Zn-doped GaAs nanowires
复制标题
气动生长的掺锌 GaAs 纳米线的复合动力学
作者：
Wei Zhang;Fangfang Yang;M. Messing;K. Mergenthaler;M. Pistol;K. Deppert;L. Samuelson;M. Magnusson;A. Yartsev
在本文中，我们研究了光生载流子的动力学在一系列的空气悬浮生长的GaAs纳米线（NWs）与不同水平的Zn掺杂。时间分辨的光致发光和瞬态吸收已被用来研究辐射（带边跃迁）和非辐射电荷复合过程，分别。我们发现，本征GaAs纳米线的光致发光（PL）的寿命显着增加后，他们的AlGaAs壳生长，表明AlGaAs壳可以有效地钝化表面的气动生长的GaAs纳米线。我们观察到PL衰减时间和PL强度随着Zn掺杂的增加而减小，这可以归因于热激活电子捕获，并且陷阱密度因Zn掺杂水平而增加。
In this paper we have investigated the dynamics of photo-generated charge carriers in a series of aerotaxy-grown GaAs nanowires (NWs) with different levels of Zn doping. Time-resolved photo-induced luminescence and transient absorption have been employed to investigate radiative (band edge transition) and non-radiative charge recombination processes, respectively. We find that the photo-luminescence (PL) lifetime of intrinsic GaAs NWs is significantly increased after growing an AlGaAs shell over them, indicating that an AlGaAs shell can effectively passivate the surface of aerotaxy-grown GaAs NWs. We observe that PL decay time as well as PL intensity decrease with increasing Zn doping, which can be attributed to thermally activated electron trapping with the trap density increased due to the Zn doping level.