Indium nitride () is a small bandgap semiconductor material which has potential application in

solar cells A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.

and high speed electronics. The bandgap of InN has now been established as ~0.7 eV depending on temperature (the obsolete value is 1.97 eV). The

effective electron mass In solid state physics, a particle's effective mass (often denoted m^*) is the mass that it ''seems'' to have when responding to forces, or the mass that it seems to have when interacting with other identical particles in a thermal distribution. ...

has been recently determined by high magnetic field measurements, m* =0.055 m₀. Alloyed with

GaN The word Gan or the initials GAN may refer to: Places *Gan, a component of Hebrew placenames literally meaning "garden" China * Gan River (Jiangxi) * Gan River (Inner Mongolia), * Gan County, in Jiangxi province * Gansu, abbreviated ''G ...

, the ternary system

InGaN Indium gallium nitride (InGaN, ) is a semiconductor material made of a mix of gallium nitride (GaN) and indium nitride (InN). It is a ternary group III/ group V direct bandgap semiconductor. Its bandgap can be tuned by varying the amount of i ...

has a direct bandgap span from the

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from aroun ...

(0.69 eV) to the

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiati ...

(3.4 eV). Currently there is research into developing solar cells using the

nitride In chemistry, a nitride is an inorganic compound of nitrogen. The "nitride" anion, N3- ion, is very elusive but compounds of nitride are numerous, although rarely naturally occuring. Some nitrides have a find applications, such as wear-resista ...

based

semiconductor A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. ...

s. Using one or more alloys of

indium gallium nitride Indium gallium nitride (InGaN, ) is a semiconductor material made of a mix of gallium nitride (GaN) and indium nitride (InN). It is a ternary group III/ group V direct bandgap semiconductor. Its bandgap can be tuned by varying the amount of i ...

(InGaN), an optical match to the

solar spectrum Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when the ...

can be achieved. The

bandgap In solid-state physics, a band gap, also called an energy gap, is an energy range in a solid where no electronic states can exist. In graphs of the electronic band structure of solids, the band gap generally refers to the energy difference ( ...

of InN allows a

wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tr ...

s as long as 1900 nm to be utilized. However, there are many difficulties to be overcome if such solar cells are to become a commercial reality: p-type doping of InN and indium-rich InGaN is one of the biggest challenges. Heteroepitaxial growth of InN with other nitrides (

AlN Aluminium nitride ( Al N) is a solid nitride of aluminium. It has a high thermal conductivity of up to 321 W/(m·K) and is an electrical insulator. Its wurtzite phase (w-AlN) has a band gap of ~6 eV at room temperature and has a potent ...

) has proved to be difficult. Thin layers of InN can be grown using

metalorganic chemical vapour deposition Metalorganic vapour-phase epitaxy (MOVPE), also known as organometallic vapour-phase epitaxy (OMVPE) or metalorganic chemical vapour deposition (MOCVD), is a chemical vapour deposition method used to produce single- or polycrystalline thin films. ...

(MOCVD).

Superconductivity

Thin polycrystalline films of indium nitride can be highly conductive and even

superconductive Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike ...

liquid helium Liquid helium is a physical state of helium at very low temperatures at standard atmospheric pressures. Liquid helium may show superfluidity. At standard pressure, the chemical element helium exists in a liquid form only at the extremely low t ...

temperatures. The superconducting transition temperature T_c depends on each sample's film structure and carrier density and varies from 0 K to about 3 K. With magnesium doping the T_c can be 3.97 K. The superconductivity persists under high magnetic field (few teslas), that differs from superconductivity in In metal which is quenched by fields of only 0.03 tesla. Nevertheless, the superconductivity is attributed to metallic indium chains or nanoclusters, where the small size increases the critical magnetic field according to the

Ginzburg–Landau theory In physics, Ginzburg–Landau theory, often called Landau–Ginzburg theory, named after Vitaly Ginzburg and Lev Landau, is a mathematical physical theory used to describe superconductivity. In its initial form, it was postulated as a phenomenol ...

References

External links

* {{Nitrides Indium compounds Nitrides III-V semiconductors III-V compounds Wurtzite structure type

Superconductivity

See also

References

External links