The thermal conductivity of tungsten diselenide (WSe2) is about 100,000 times that of diamond, the best thermal conductivity material, and is the lowest thermal conductivity material in the world. Researchers at the Vienna University of Technology in Austria have developed for the first time a diode made of tungsten diselenide (WSe2), which experiments show that this material can be used in ultrathin soft Sexual solar cells. Tungsten diselenide (WSe2), the main structure is composed of upper and lower layers of selenium atoms connected to the middle layer of tungsten atoms. The WSe2 material, like graphene, absorbs light, and the absorbed light can be used to generate electricity.

This thin layer is indeed light and thin, allowing about 95% of the light to pass through, but one-tenth of the remaining 5% is absorbed by the material and converted into electricity. Therefore, its internal efficiency is quite high. If multiple ultrathin layers are stacked on top of each other, a large fraction of this incoming light can be used effectively -- but sometimes this high transparency can have a beneficial side effect. Heat is transferred in the form of phonons in the crystal, so if the crystal structure is fairly regular, the phonons can easily travel far away, that is, with high thermal conductivity. Conversely, if the regularity of the atomic structure of the lattice is very poor, the phonons will quickly dissipate energy in the lattice, and the thermal conductivity of the material will naturally be poor.

This new material not only has thermal conductivity like a porous material. More importantly, it has a high density, about the same as copper.Due to the huge application potential of tungsten diselenide, Juna Group has long provided high-performance tungsten diselenide (WSe2) materials to the world's top scientific research institutes.

Recently, researchers at MIT have discovered that a 2D material called tungsten diselenide (WSe2) has the potential to manipulate optoelectronic interactions in various applications such as lighting, displays, optical interconnects, logic and sensors. The ability to optimize efficiency and spectral properties can also be used to develop ultra-thin, lightweight and flexible photovoltaic cells, enhanced LEDs and other optoelectronic devices. The research results were published in the journal Nature Nanotechnology (doi: 10.1038/nnano.2014.26).

The research team used half-N-type and half-P-type electrically doped WSe2 materials to create functioning diodes and were also able to create basic optoelectronic devices such as photodetectors, photovoltaic cells and LEDs. Electroluminescence is the main mechanism, which has been observed in existing 2D molybdenum disulfide (MoS2) devices, the researchers said. However, MoS2 has poor optical quality due to its low luminous efficiency and wide spectral linewidth. The latest research has observed electroluminescence effect in the lateral P-N junction of 2D WSe2, and the optical quality of WSe2 is high. The researchers used thin boron nitride pillars as a dielectric layer and placed multiple metal gates beneath them to achieve electrostatically induced electroluminescence. This structure enables efficient electron and hole injection, which, combined with the high optical quality of WSe2, can produce bright electroluminescence with 1000 times smaller injection current and 10 times narrower line width than MoS2.

According to the researchers, the system will become an essential part of the future development of new optoelectronic devices such as spin/valley-polarized LEDs, on-chip lasers, and 2D electro-optic modulators. At the same time, WSe2 materials can also be used in solar cells and display devices, which in turn will be used in building or vehicle windows and even clothing.