Revealing charge carrier dynamics and transport in Te-doped GaAsSb and GaAsSbN nanowires by correlating ultrafast terahertz spectroscopy and optoelectronic characterization
Revealing charge carrier dynamics and transport in Te-doped GaAsSb and GaAsSbN nanowires by correlating ultrafast terahertz spectroscopy and optoelectronic characterization
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DOI：
10.1088/1361-6528/ac7d61
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发表时间：
2022-10-15
期刊：
影响因子：
3.5
通讯作者：
Prasankumar，Rohit P.
中科院分区：
文献类型：
--
作者：
Yuan，Long;Pokharel，Rabin;Prasankumar，Rohit P.
III-V型半导体纳米线（NWs）的最新进展为纳米级光电器件的应用带来了巨大的希望。在III-V型半导体NWs中加入少量氮(N)可以有效地红移其工作波长，并根据特定应用定制其电子特性。然而，了解N掺入对半导体NW中非平衡电荷载流子动力学和输运的影响是实现高效半导体NW器件的关键。在这项工作中，超快光泵浦-太赫兹探针光谱被用于研究te掺杂GaAsSb和稀氮化GaAsSbN NWs的非平衡载流子动力学和输运，目的是将这些结果与它们在偏置和低频噪声特性下的平衡光响应的电学表征联系起来。氮在GaAsSb NWs中的掺入导致载流子散射速率显著增加，导致载流子迁移率严重降低。在GaAsSbN和GaAsSb NWs中，载流子重组寿命分别为33±1皮秒（ps）和147±3ps。载流子寿命和光致光学电导率的降低是由于n诱导缺陷的存在，导致稀氮化NWs的电学和光学特性相对于非氮化NWs的恶化。最后，我们观察到两种NW材料的上升时间都非常快，为2 ps，直接影响了它们作为高速光电探测器的潜在用途。
Recent advances in the growth of III-V semiconductor nanowires (NWs) hold great promise for nanoscale optoelectronic device applications. It is established that a small amount of nitrogen (N) incorporation in III-V semiconductor NWs can effectively red-shift their wavelength of operation and tailor their electronic properties for specific applications. However, understanding the impact of N incorporation on non-equilibrium charge carrier dynamics and transport in semiconducting NWs is critical in achieving efficient semiconducting NW devices. In this work, ultrafast optical pump-terahertz probe spectroscopy has been used to study non-equilibrium carrier dynamics and transport in Te-doped GaAsSb and dilute nitride GaAsSbN NWs, with the goal of correlating these results with electrical characterization of their equilibrium photo-response under bias and low-frequency noise characteristics. Nitrogen incorporation in GaAsSb NWs led to a significant increase in the carrier scattering rate, resulting in a severe reduction in carrier mobility. Carrier recombination lifetimes of 33±1 picoseconds (ps) and 147±3 ps in GaAsSbN and GaAsSb NWs, respectively, were measured. The reduction in the carrier lifetime and photoinduced optical conductivities are due to the presence of N-induced defects, leading to deterioration in the electrical and optical characteristics of dilute nitride NWs relative to the non-nitride NWs. Finally, we observed a very fast rise time of∼ 2 ps for both NW materials, directly impacting their potential use as high-speed photodetectors.