GaN Nanowire/Nb-Doped MoS₂ Nanoflake Heterostructures for Fast UV–Visible Photodetectors

Abstract

gallium nitride (GaN) has been used as building blocks to construct optoelectronic nanodevices because of its properties. However, the slow respond speed and narrow spectral detection range of nano-based devices hardly meet the requirements of high-speed and multifunction component development. Herein, we propose a promising strategy to realize photodetectors (PDs) featuring high responsivity, fast response speed, and a wide spectral response range by constructing GaN nanowire/Nb-doped MoS 2 flake hybrid heterostructures. Thanks to the synergistic effect of GaN and doped MoS 2 , the integrated device exhibits high responsivity for ultraviolet (365 nm) as well as visible (500 nm) light, and the maximum value is 1.7 × 10 2 and 0.34 A/W. For UV detection, the integrated device shows fast response and its rise/fall time is <8/10 ms, which can rival or surpass many 1D nano-based PDs. Further investigation confirms that the type-II band alignment of the GaN/doped MoS 2 heterojunction with a conduction band offset and a valence band offset of 0.19 and 2.09 eV, respectively, contributes to the enhanced photogenerated carrier separation and transfer process. The assembled PDs with broad-spectrum photoresponse and fast response speed have great promise as the next-generation hybrid photodetection devices.

Broadband MoS2 Square Nanotube-Based Photodetectors

“…The I – V curves show a linear relationship between the current and the applied bias voltage, indicating that an ohmic contact has been formed between the nanotubes and Ag electrodes. The photocurrent increases significantly with increasing incident light power density, which can be attributed to more incident light absorption, leading to more photogenerated carriers . In addition, the I – V curves show n-type behavior, again indicating that the MoS 2 nanotubes are n-type semiconductors.…”

“…The photocurrent increases significantly with increasing incident light power density, which can be attributed to more incident light absorption, leading to more photogenerated carriers. 41 In addition, the I−V curves show n-type behavior, again indicating that the MoS 2 nanotubes are n-type semiconductors. Compared with UV and vis light irradiation, the PD obtains Information, the dynamic photoresponse of the detector under different bias voltages is extremely stable, reflecting the excellent stability of the device.…”

Bi2O2Se Nanowire/MoSe2 Mixed-Dimensional Polarization-Sensitive Photodiode with a Nanoscale Ultrafast-Response Channel

“…As a result, the corresponding photodetector can increase the number of photo-induced minority carriers and broaden the interface channels to improve the carrier transport efficiency, resulting in a high detectivity of 1.64 × 10 11 Jones and a fast response of 50 μs under 532 nm irradiation at V ds = −2 V . A UV photodetector based on GaN nanowires/Nb-Doped MoS 2 nanoflakes with a high responsivity of 1.7 × 10 2 A/W and a rise/fall time of 8/10 ms is reported by Tang et al Above all, 1D/2D vdWs heterostructures offer a novel avenue for designing multifunctional optoelectronics with trade-off performance and unique characteristics.…”

The influence of Fermi level position at the GaN surface on carrier transfer across the MAPbI3/GaN interface

“…4 Nowadays, it also successfully acts as a reliable platform for tandem devices taking on board emerging materials such as van der Waals crystals and perovskites, which results in the demonstration of solar cells, 5 LEDs, 6,7 transistors 8 and photodetectors. 9,10 All presently proposed optoelectronic devices are multilayered, based on heterostructures with multiple interfaces. 11 In this circumstance, the famous phrase “the interface is the device” evoked by H. Kroemer in his Nobel Lecture is as relevant as ever.…”