Effect of low-energy electron beam irradiation on the current-voltage characteristics of single-walled carbon nanotube field effect transistors

摘要

We have performed a series of electrical characterizations on single-walled carbon nanotube (SWCNT) bundle-field effect transistors (FETs) pre- and post-irradiation with low-energy electron beam of 2.5 KeV via scanning electron microscope (SEM). The devices were configured in a geometry where a bundle of SWCNT of approximately 50 nm in diameter was placed across two gold contacts. Current-voltage (I-V) sweep was performed by placing probes on two gold contacts and running a sweep under the gate voltages (Vg) of 0 to 500 mV in 100 mV increments. The characterization shows that our device behaves as a symmetric semiconducting device. In addition, we observe hysteresis behavior between I-V curves under pre-and post-electron beam irradiation for 30 seconds. We observe that immediately after irradiating our device under the SEM, the maximum current value is lower across the device compared to pre-irradiation value. Furthermore, I-V sweep 17 hours post-irradiation shows higher maximum current value compared to the initial, pre-irradiation value. This behavior of decreased, then increased current values also demonstrate a possible rectifying characteristic of the SWCNT bundle FET device. Additionally, we performed I-V sweep from 0 to 5 V under various gate biases of 0 to 500 mVs. The data reveals that at Vg = 200 mV, there is a sharp break in the current value that is not rectified. The SEM image post-measurement confirms that SWCNT bundle has been completely removed due to the short circuiting of the device during I-V sweep under high gate bias condition. The results presented in this proceeding may prove valueable in research and development of single, as well as bundled SWCNT miniaturized electronic devices and the effects of low-energy radiation on them.