The electrical properties of boron nitride (BN) nanostructures, particularly BN nanotubes (NTs), have been studied less in comparison to the counterpart carbon nanotubes. The present work investigates the field emission (FE) behavior of BNNTs under multiple cycles of FE experiments and demonstrates a strain-engineering pathway to tune the electronic properties of BNNTs. The electrical probing of individual BNNTs were conducted inside a transmission electron microscope (TEM) using an insitu electrical holder capable of applying a bias voltage of up to 110V. Our results indicate that in the first cycle a single BNNT can exhibit the current density of ～1 mA cm ~(-2) at 110V and the turn-on voltage of 325Vμm ~(-1). However, field emission properties reduced considerably in subsequent cycles. Real-time imaging revealed the structural degradation of individual BNNTs during FE experiments. The electromechanical measurements show that the conductivity of BNNTs can be tuned by means of mechanical straining. The resistance of individual BNNTs reduced from 2000 to 769M and the carrier concentration increased from 0.35×10 ~(17) to 1.1×10 ~(17)cm ~(-3) by straining the samples up to 2.5%.
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机译：与相应的碳纳米管相比，对氮化硼（BN）纳米结构，尤其是BN纳米管（NTs）的电性能研究较少。本工作调查了在有限元实验的多个循环下BNNTs的场发射（FE）行为，并演示了一种应变工程途径来调节BNNTs的电子特性。使用能够施加高达110V偏置电压的原位电支架在透射电子显微镜（TEM）内对单个BNNT进行电探测。我们的结果表明，在第一个循环中，单个BNNT在110V时的电流密度为〜1 mA cm〜（-2），在325Vμm〜（-1）的情况下会导通。然而，场发射特性在随后的循环中大大降低。实时成像揭示了有限元实验期间单个BNNT的结构退化。机电测量表明，可以通过机械应变来调节BNNT的电导率。通过将样品拉紧至2.5％，单个BNNT的电阻从2000降低到769M，载流子浓度从0.35×10〜（17）增加到1.1×10〜（17）cm〜（-3）。
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