High-Efficiency Monolayer Molybdenum Ditelluride Light-Emitting Diode and Photodetector

Abstract

Developing a high efficiency and low-cost light source with emission wavelength transparent to silicon is an essential step toward silicon based nanophotonic devices and micro/nano industry platforms. Here we demonstrate a near infrared monolayer MoTe2 light emitting diode (LED) that emission transparent to silicon. By taking advantage of the quantum tunneling effect, the device has achieved a very high external quantum efficiency (EQE) of 9.5% at 83 K, which is the highest EQE obtained from LED devices fabricated from monolayer TMDs so far. When the device is operated as a photodetector, the MoTe2 device exhibits a strong photoresponsivity at resonant wavelength 1145 nm. The low dark current of ~5pA and fast response time 5.06 ms are achieved due to suppression of hBN tunneling layer. Our results open a new route for the investigation of novel near infrared silicon integrated optoelectronic devices.

Van der Waals 2D Transition Metal Tellurides

“…The bandgap of TMTs varies from 0 to 1.1 eV, which have the potentiality for photodetectors, especially at the infrared wavelength . For example, MoTe 2 was applied for ultraviolet, visible light, and infrared detection . The ultraviolet photodetection performance has been probed in a MoTe 2 –MoS 2 heterostructure by He and co‐workers as illustrated in Figure a .…”

“…The electroluminescence (EL) mapping is shown in Figure a . Besides, Lu and co‐workers introduced the h‐BN as the tunneling layer and the graphene as the electrodes in the monolayer MoTe 2 LED devices . A very high external quantum efficiency has been achieved, which was 9.5% at injection current of 75.9 nA µm −2 , following the Fowler–Nordheim tunneling model .…”

“…Besides, Lu and co‐workers introduced the h‐BN as the tunneling layer and the graphene as the electrodes in the monolayer MoTe 2 LED devices . A very high external quantum efficiency has been achieved, which was 9.5% at injection current of 75.9 nA µm −2 , following the Fowler–Nordheim tunneling model . The research and discovery of low power consumption, high luminescent efficiency, high stability, and long‐life 2D LED sources will be a magnet for researchers in the future.…”

An Adaptive Soft Plasmonic Nanosheet Resonator

“…This type of technology can also be combined with low-dimensional materials for future optomechanical devices. [25][26][27][28][29][30][31][32]…”

“…Due to the advanced near field light–matter interaction inside the plasmonic nanosheet, the resonance frequency is adaptive to either incident light intensity or incident wavelength which gives the proposed device a substantially robust and adaptive response. This type of technology can also be combined with low‐dimensional materials for future opto‐mechanical devices …”