폭발물 감지 시스템 개발을 위한 TNT 분자 흡착에 대한 WSe2 소자의 전기적 반응 특성 평가 = Electrical response of tungsten diselenide to the adsorption of trinitrotoluene molecules

다국어 초록 (Multilingual Abstract)

As demanding the detection of explosive molecules, it is required to develop rapidly and precisely responsivesensors with ultra-high sensitivity. Since two-dimensional semiconductors have an atomically thin body nature where mobilecarriers accumulate, the abrupt modulation carrier in the thin body channel can be expected. To investigate the effectivenessof WSe2 semiconductor materials as a detection material for TNT (Trinitrotoluene) explosives, WSe2 was synthesized using thermal chemical vapor deposition, and afterward, WSe2 FETs (Field Effect Transistors) were fabricated using standard photo-lithograph processes. Raman Spectrum and FT-IR (Fourier-transform infrared) spectroscopy reveal that the adsorption of TNT molecules induces the structural transition of WSe2 crystalline. The electrical properties before and after adsorption of TNT molecules on the WSe2 surface were compared; as 50 V was applied as the back gate bias, 0.02 A was recorded in the bare state, and the drain current increased to 0.41 A with a dropping 0.6% (w/v) TNT while maintaining the p-type behavior. Afterward, the electrical characteristics were additionally evaluated by comparing the carrier mobility, hysteresis, and on/off ratio. Consequently, the present report provides the milestone for developing ultra-sensitive sensors with rapid response and high precision.