Facile fabrication of a ultraviolet tunable MoS2/p-Si junction diode

Abstract

Chemical vapor deposition grown MoS2 single crystals were transferred onto the edge of a p-Si/SiO2 wafer, forming an abrupt heterogeneous junction diode at the MoS2/p-Si interface. When electrically characterized as a field effect transistor, MoS2 exhibits an n-type response and can be doped in the presence of ultraviolet (UV) light. As a diode, it operates satisfactorily in air, but has higher currents in vacuum with a turn on voltage of ∼1.3 V and an on/off ratio of 20 at ±2 V. UV irradiation increases the diode on state current, decreases the turn-on voltage, and reduces the ideality parameter below 2. These changes are reversible after annealing in air as desorption of electron trapping species like O2− and H2O− are believed responsible for this effect. A circuit integrating this diode was used to rectify a 1 kHz signal with an efficiency of 12%. Its simple design, coupled with the ability to clip AC signals, sense UV light, and reversibly tune these diodes, makes them inexpensive, multifunctional, and usable as active or passive circuit components in complex electronics.

Poly(lactic acid)/poly(3‐hexylthiophene) composite nanofiber fabrication for electronic applications

“…The resultant p–n diode was formed along the perpendicular edge of the substrate at the nanofiber/n‐doped Si interface. Such diodes were prepared by us in the past using a similar construction technique with different materials …”

Rectifying effect in a MoS2 monolayer crossed with an electro-spun PEDOT-PSS nano-ribbon

“…Controlled growth of monolayer MoS 2 on Si + /SiO 2 substrates used in this work has been reported elsewhere [19]. After growth, the MoS 2 crystals were transferred to clean pre-patterned or un-patterned Si + /SiO 2 substrates (200 nm oxide thickness) via the use of a spin-coated PMMA film and a subsequent KOH oxide etch [20]. Some reasons for this transfer were: to avoid the possibility of using a substrate with a damaged oxide layer during CVD growth; to use new substrates that were pre-patterned and hence useful in a field-effect transistor configuration (FET); to increase the spacing between MoS 2 crystals on the new substrates, and hence fabricate an isolated MoS 2 /PEDOT-PSS junction that eliminates cross-interference from other diodes.…”

Band Structure Engineering in 2D Materials for Optoelectronic Applications

“…Aside from 2D heterostructures, hybrid devices that consist of a 2D‐layered material and a traditional semiconductor, e.g., Si, organic/inorganic semiconductors, or carbon nanotubes, have been intensively studied recently. Such a combination has a facile fabrication process but brings novel functionalities and enhanced performance that is not found in a single component . Depending on the operation requirement, the hybrid p–n junction can not only inject electrons and holes that recombine to give out photon emission in light‐emitting devices, but also facilitate exciton separation and charge extraction under the built‐in electric field.…”

“…Depending on the operation requirement, the hybrid p–n junction can not only inject electrons and holes that recombine to give out photon emission in light‐emitting devices, but also facilitate exciton separation and charge extraction under the built‐in electric field. When n‐type MoS 2 was introduced to p‐type Si with the aligned transfer, a type II heterojunction was formed, which is able to operate as an inorganic solar cell, a LED, or a photodetector . It is even simpler to deposit organic semiconductors, e.g., pentacene, rubrene, etc., on the 2D material to form organic semiconductor–2D material van der Waals p–n junctions.…”