Surface nanostructuring and passivation for light coupling at the interface of SiC based optoelectronic devices

Speaker:Prof.Haiyan Ou (DTU Fotonic)

Time and Date: 14:00- , Jun. 30, 2015

Place: Room B415, Computing Centre Building, Handan Campus

 

 

Abstract

There is always a huge loss when light tries to penetrate from an interface where large index contrast exists between the two materials. In this talk, SiC is chosen as an example because it is emerging as a promising wavelength conversion material to take the place of the current phosphors for the new generation light-emitting diodes white light source. A couple of nanofabrication technologies are developed (e-beam lithography, nanosphere lithography, metal self-assembly, and Al thin film) and compared with respect to their cost, time consumption, reflectance suppression, and transmittance increase. All these technologies have demonstrated very high (up to 106%) photoluminescence enhancement. To reduce the surface defects and damages caused by the dry etching of SiC, both TiO2 and Al2O3 thin films have been tried by using atomic layer deposition on the nanostructured surface. Further photoluminescence enhancement is observed after the surface passivation. The total photoluminescence enhancement achieved so far exceeds the extraction efficiency enhancement from the surface nanostructures. More investigations on the physics behind need to be carried out.

 

 

Biography

Haiyan Ou received her Ph D degree in semiconductor devices and microelectronics from the Institute of Semiconductors, Chinese Academy of Sciences in 2000. From 2000, she has joined Technical University of Denmark (DTU), where she was promoted as associate professor in 2005. She was a JSPS (Japanese Society for promotion of Science) fellow at Meijo University (2011), and a visiting professor at the Institute of Semiconductors, Chinese Academy of Science (2011). She was the co-organizer of the symposium G at E-MRS 2013, and the LED symposium at PIERS 2014. Her scientific background is in the areas of materials and devices for optical communication, photovoltaics and light emission. She has led a number of national projects and is managing a 7 researcher team daily. She has published more than 152 peer-reviewed journal and conference papers, including one in prestigious journal Nature and 8 invited talks at international conferences. She is the founder of Light Extraction ApS. She is winner of the 2013 strategic research award for research with great innovation potential from the Danish council for strategic research. She is in the editorial board of Scientific Reports.