Xiamen University, using ultra-thin aluminum film to crack the deep UV LED conundrum

Xiamen University by a research team in the the high alumina component nitride deep ultraviolet light-emitting diode surface covered with ultra-thin aluminum film to crack the key challenges restricting the light-emitting devices can be more widely used "light extraction efficiency for the futuresuch devices in industrial applications in areas such as health care, environmental protection, military open to new methods and ideas.

Building Physics and Electrical Engineering Professor 64 and 128 atom supercells the geometric study group's research team after several years of research, the research team associate professor Huang Kai and doctoral high Na borrow an ultra-thin aluminum film to crack the puzzle. When in a deep ultraviolet light-emitting diode surface coated with a layer of only 5 nm ultra-thin aluminum film layer aluminum film not only does not like a traditional mirror as the device emitted light reflected back, instead cleverly devices to side emitted light is collected through an aluminum film layer, is emitted from the front, to achieve improvement of light extraction efficiency.

David Wong explained, this is because after the aluminum film is made ​​very thin, in which the nano effects make it different from the traditional mirror the light reflected back, but rather focus to absorb light collection and positive emission.

The tests showed that the "coat" of this layer of aluminum on the contribution of the UV light emitting diode light extraction efficiency will vary with the different wavelengths. Generally speaking, the shorter the wavelength of light, the higher the efficiency. Data show that same plating on this layer of aluminum film, a wavelength of about 310 nm ultraviolet light emitting diode, the light extraction efficiency can be improved by about 20%; wavelength of about 290 nm ultraviolet light-emitting diode, the light extraction efficiency can be increased by about 50%; a wavelength of approximately 280 nm deep ultraviolet light-emitting diode, the light extraction efficiency can be increased to 130%.