Low-Voltage Operating Field-Effect Transistors and Inverters Based on In₂O₃ Nanofiber Networks

Electrospinning one-dimensional (1-D) semiconductor nanofibers have been regarded as one of the most promising building blocks for future nanoelectronics with high performance because they can exhibit a broad range of device functions. However, electronic devices based on electrospinning-driven nanofibers often suffer from poor performance and inferior quality. In current works, continuous and uniform high-quality indium oxide (In
₂
O
₃
) nanofibers were obtained by electrospinning. The surface morphology, crystallinity, optical, and electrical properties of the In
₂
O
₃
nanofibers were investigated by X-ray diffraction, scanning electron microscopy, optical spectroscopy, and electrical measurements. It has been detected that the field-effect transistors (FETs) with optimized electrospinning time of 30 s demonstrated superior electrical performance, including a high field-effect mobility ( μ
_FE
) of 9.1 cm
²
·V
^-1
·
^-1
and a large I
_ON
/I
_OFF
of 10
⁷
. The high- k Al
₂
O
₃
dielectric layer has also been used to greatly reduce the operating voltage (from 30 to 3 V), significantly improve μ
_FE
(to 27.7 cm
²
·V
^-1
·
^-1
), and strengthen stability over cycling. To prove the device's potential in more complex logic circuit applications, a resistor-loaded inverter was further integrated, and the maximum voltage gain of 9.8 was demonstrated at an ultralow operating voltage of 3 V. The present findings have demonstrated that electrospinning can potentially be used as a straightforward and cost-effective means for the assembly of 1-D nanostructures for use in next-generation low-power devices.