We explore the effects of random and short-period crystal-phase intermixing in InAs nanowires (NW) on the carrier trapping and thermal activation behavior using correlated optical and electrical transport spectroscopy. The polytypic InAs NWs are grown by catalyst-free molecular beam epitaxy under different temperatures, resulting in different fractions of wurtzite (WZ) and zincblende (ZB) and variable short-period (∼1–4 nm) WZ/ZB stacking sequences. Temperature-dependent microphotoluminescence $\left(\mu \text{PL}\right)$ studies reveal that variations in the WZ/ZB stacking govern the emission energy and carrier confinement properties. The optical transition energies are modeled for a wide range of WZ/ZB stacking sequences using a Kronig-Penney type effective mass approximation, while comparison with experimental results suggests that polarization sheet charges on the order of ∼0.0016–0.08 C/m along the WZ/ZB interfaces need to be considered to best describe the data. The thermal activation characteristics of carriers trapped inside the short-period WZ/ZB structure are directly reproduced in the temperature-dependent carrier density evolution (4–300 K) probed by four-terminal (4T) NW-field effect transistor measurements. In particular, we find that activation of carriers in-between $\sim {10}^{16}-{10}^{17}\mathrm{c}{\mathrm{m}}^{-3}$ follows a two-step process, with activation at low temperature attributed to WZ/ZB traps and activation at high temperature being linked to surface states and electron accumulation at the InAs NW surface.

中文翻译：

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多型InAs纳米线中短周期纤锌矿/闪锌矿堆叠序列的载流子俘获和活化

我们使用相关的光学和电传输光谱技术，研究了InAs纳米线（NW）中随机和短周期晶相混合对载流子俘获和热活化行为的影响。多型InAs NW通过无催化剂分子束外延在不同温度下生长，导致纤锌矿（WZ）和闪锌矿（ZB）的馏分不同，并具有可变的短周期（〜1-4 nm）WZ / ZB堆积顺序。温度依赖性微光致发光$（\mu \text{PL}）$研究表明，WZ / ZB堆叠中的变化控制着发射能量和载流子限制特性。使用Kronig-Penney型有效质量近似法对各种WZ / ZB堆叠序列的光学跃迁能进行建模，而与实验结果的比较表明，偏振片沿WZ的电荷约为0.0016–0.08 C / m需要考虑/ ZB接口以最好地描述数据。短周期WZ / ZB结构内捕获的载流子的热激活特性直接通过四端（4T）NW场效应晶体管测量所探测到的温度相关载流子密度演变（4-300 K）直接再现。特别是，我们发现之间的载流子激活$〜{10}^{16}-{10}^{17}\mathrm{C}{\mathrm{米}}^{-3}$ 遵循两步过程，归因于WZ / ZB陷阱的低温激活和高温的激活与InAs NW表面的表面状态和电子积累有关。