Zhang Kailing, Li Xinxin, Dai Weitao, Toor Fatima, Prineas J P
Nano Lett. 2019 Jul 10;19(7):4272-4278. doi: 10.1021/acs.nanolett.9b00517. Epub 2019 Jun 21.
We report on carrier recombination within self-catalyzed InAs/InAlAs core-shell nanowires (NWs), disentangling recombination rates at the ends, sidewalls, and interior of the NWs. Ultrafast optical pump-probe spectroscopy measurements were performed from 77-293 K on the free-standing, variable-sized NWs grown on lattice-mismatched Si(111) substrates, independently varying NW length and diameter. We found NW carrier recombination in the interior is nontrivial compared to the surface recombination, especially at 293 K. Surface recombination is dominated by carrier recombination at the NW sidewall, while contributions from the highly strained, impure NW base are negligible.
我们报告了自催化生长的InAs/InAlAs核壳纳米线（NWs）中的载流子复合情况，解析了纳米线端部、侧壁和内部的复合速率。在77至293K温度范围内，对生长在晶格失配的Si(111)衬底上的独立可变尺寸的自支撑纳米线进行了超快光泵浦-探测光谱测量，纳米线的长度和直径可独立变化。我们发现，与表面复合相比，纳米线内部的载流子复合情况较为复杂，尤其是在293K时。表面复合主要由纳米线侧壁的载流子复合主导，而高度应变、不纯的纳米线基部的贡献可忽略不计。
