A mixed-dimensional light-emitting diode based on a p-MoS₂ nanosheet and an n-CdSe nanowire

Abstract

The construction of the mixed-dimensional van der Waals (vdW) heterostructures with two-dimensional (2D) and one-dimensional (1D) materials can advantageously integrate their respective dimensional properties to produce new device functionalities and/or enhance device performance. In this case, a single semiconductor nanowire (NW) can function as an optical cavity and a gain medium, while the atomically thin 2D material does not strongly absorb the NW's light emission or disturb the optical propagation mode. Therefore, the mixed-dimensional 2D/1D vdW heterostructure might provide a new route to realize high-efficiency light-emitting diodes (LEDs) and/or even electrically driven lasers. Here, we report a LED based on a p-type MoS nanosheet and an n-type CdSe NW. The 2D/1D vdW heterojunction diode exhibits a rectification ratio of ∼24 at V = ±3 V, and a low turn-on voltage of ∼1.5 V. Under the forward bias exceeding the turn-on voltage, the 2D/1D vdW heterojunction exhibits strong electroluminescence centered at ∼709 nm, corresponding to the band-edge emission of the CdSe NW. This novel 2D/1D vdW device, which takes advantages of both 2D and 1D semiconductors, enables potential future applications in electrically driven lasers, high-sensitivity sensors, and transparent flexible devices.

Van der Waals heterostructures with one-dimensional atomic crystals

“…For the staggered gap, the band gap of different components is partly overlapped. Such type of band alignment would greatly facilitate the transfer and separation of electrons and holes, and it has been widely utilized to construct heterostructures for photovoltaic devices [142,159]. In the case of broken gap, carrier transport occurs through the quantum tunnelling effect followed by the diffusion of majority carriers, thereby leading to the negative differential resistance at heterojunction.…”

Cadmium Selenide Quantum Dots for Solar Cell Applications: A Review

“…A direct bandgap ( 1.74 eV at 300 K) and a high absorption coefficient make onedimensional (1D) CdSe nanomaterials a strong contender for high-performance photodetectors, SCs, field-effect transistors, light-emitting diodes, lasers, etc. [19][20][21][22][23][24] The microwave-assisted (MWA) technique is used widely to synthesize both organic and inorganic materials. [25][26][27][28][29][30] It is also an excellent technique for processing nanoparticles (NPs), compared with traditional heating.…”

“…Nanomaterials with low‐dimensional CdSe exhibit distinct physical and geometric characteristics and have been thoroughly studied in terms of both basic principles and practical applications. A direct bandgap (∼1.74 eV at 300 K) and a high absorption coefficient make one‐dimensional (1D) CdSe nanomaterials a strong contender for high‐performance photodetectors, SCs, field‐effect transistors, light‐emitting diodes, lasers, etc [19–24] …”

Review on Quasi One-Dimensional CdSe Nanomaterials: Synthesis and Application in Photodetectors

“…A direct bandgap (~1.74 eV at 300 K for bulk) and a high absorption coefficient near the band edge, make 1D CdSe nanomaterials a good choice for the design in next-generation high-performance photodetectors, solar cells, light-emitting diodes, field-effect transistors, and lasers, etc. [7,8,9,10,11,12].…”