p–n hetero-junction diode arrays of p-type single walled carbon nanotubes and aligned n-type SnO₂nanowires

Abstract

p-n hetero-junction diode arrays were fabricated using specific direct techniques for the transfer of p-type single walled carbon nanotubes (SWCNTs) and aligned n-type SnO₂ nanowires (NWs) onto a patterned substrate surface. Their electronic and optoelectronic properties were characterized. Perpendicular crossings of the p- and the n-channels with each other were confirmed by transfer characteristics with respect to the bottom gate. The resulting diode showed a good rectifying behavior with a rectification ratio of over 10² at ±5 V, where the equivalent circuit model of a serially connected diode and resistor was used for analysis of the electrical properties. Both the forward and the reverse currents were observed to increase with the application of a positive gate bias, indicating an n-type gate dependence. Under a forward bias, the dominant contribution of the SnO₂ NW channel to the total resistance of the equivalent model is attributed to the n-type gate dependence since the resistance of the n-channel increased with a negative gate bias, resulting in the decrease of the forward current. Under a reverse bias, positive gate increased the concentration of valence electrons in the SWCNTs, enhancing direct tunneling to the conduction band of the SnO₂ NWs. High sensitivity to UV irradiation under the reverse bias was also demonstrated with a photosensitivity over 10², suggesting potential applicability of the hetero-junction diodes in optoelectronic devices.

Fabrication of Stretchable Single‐Walled Carbon Nanotube Logic Devices

“…SWCNTs synthesized by chemical vapor deposition (CVD) are transferred onto a substrate by thermal release tape transfer method. [ 41 ] Source and drain electrodes of Pd (50 nm) are deposited by e-beam evaporation. For partial doping of the pristine SWCNT channel, NADH solution (10 mM diluted in DI-water) is drop-coated in the desired area of the channel, dried at 60 °C to evaporate the DI-water, and annealed at 150 °C for 10 min for electron donation from NADH to the SWCNTs.…”

“…The 400 nm thick PVP layer is then spin coated for the gate dielectric layer. SWCNTs synthesized by chemical vapor deposition (CVD) are transferred onto a substrate by thermal release tape transfer method . Source and drain electrodes of Pd (50 nm) are deposited by e‐beam evaporation.…”

“…The CVD-grown SWCNTs were transferred onto a substrate via previously reported thermal release tape transfer method. [ 41 ] Source and drain electrodes of Pd (50 nm) were deposited by e-beam evaporation. To confi ne the channel area, residual SWCNTs were removed by reactive ion etching (O 2 , 10 mTorr, 100 W, 20 sccm, 30 sec).…”

“…The spin‐coated PVP dielectric layer showed a good insulating property with a very small leakage current under the gate bias voltage between ‐10 and +10 V as shown in the Figure S5. The CVD‐grown SWCNTs were transferred onto a substrate via previously reported thermal release tape transfer method . Source and drain electrodes of Pd (50 nm) were deposited by e‐beam evaporation.…”

Fabrication of flexible micro-supercapacitor array with patterned graphene foam/MWNT-COOH/MnO electrodes and its application

“…The PVA-H 3 PO 4 electrolyte was drop-coated on the electrodes and dried for 12 h at room temperature. CVD-grown SnO 2 NWs were transferred onto a SiO 2 /Si substrate via our previously reported sliding transfer technique [36][37]. The Au/Ti source and drain electrodes were deposited on the transferred SnO 2 NWs and the resistor type SnO 2 NW UV sensor was fabricated by photolithography.…”