Lee Youngmin, Jun Hyewon, Park Seoyeon, Kim Deuk Young, Lee Sejoon
Department of Semiconductor Science, Dongguk University-Seoul, Seoul 04620, Republic of Korea.
Quantum-Functional Semiconductor Research Center, Dongguk University-Seoul, Seoul 04620, Republic of Korea.
Nanomaterials (Basel). 2023 Jun 5;13(11):1809. doi: 10.3390/nano13111809.
The transport characteristics of a gate-all-around Si multiple-quantum-dot (QD) transistor were studied by means of experimental parametrization using theoretical models. The device was fabricated by using the -beam lithographically patterned Si nanowire channel, in which the ultrasmall QDs were self-created along the Si nanowire due to its volumetric undulation. Owing to the large quantum-level spacings of the self-formed ultrasmall QDs, the device clearly exhibited both Coulomb blockade oscillation (CBO) and negative differential conductance (NDC) characteristics at room temperature. Furthermore, it was also observed that both CBO and NDC could evolve along the extended blockade region within wide gate and drain bias voltage ranges. By analyzing the experimental device parameters using the simple theoretical single-hole-tunneling models, the fabricated QD transistor was confirmed as comprising the double-dot system. Consequently, based on the analytical energy-band diagram, we found that the formation of ultrasmall QDs with imbalanced energetic natures (i.e., imbalanced quantum energy states and their imbalanced capacitive-coupling strengths between the two dots) could lead to effective CBO/NDC evolution in wide bias voltage ranges.
通过使用理论模型进行实验参数化研究了全栅硅多量子点（QD）晶体管的输运特性。该器件采用电子束光刻图案化的硅纳米线沟道制造，由于硅纳米线的体积起伏，超小量子点沿硅纳米线自发生成。由于自形成的超小量子点具有较大的量子能级间距，该器件在室温下清晰地展现出库仑阻塞振荡（CBO）和负微分电导（NDC）特性。此外，还观察到CBO和NDC在宽栅极和漏极偏置电压范围内均可沿扩展的阻塞区域演变。通过使用简单的理论单空穴隧穿模型分析实验器件参数，证实所制造的量子点晶体管由双量子点系统组成。因此，基于分析能带图，我们发现具有不平衡能量性质（即两个量子点之间量子能态不平衡及其电容耦合强度不平衡）的超小量子点的形成可导致在宽偏置电压范围内有效CBO/NDC演变。
