Title: Fluorescent and photovoltaic SiC: a new research field
When: Thursday 21 november, 12:h00
Where: Sala de grados módulo 8, Facultad de Ciencias.

Speaker: Mikael Syväjärvi, Linköping University, Sweden
Semiconductor Energy and Environmental Materials research

Silicon carbide has re-emerged as a potential host material for light emtting and photovoltaic applications by new concepts. These are based on doping of SiC to achieve the optoelectronic properties. The performance of the material is closely related to crystal growth phenomena. We will introduce the basic concepts for the white LED and solar cell, and outline the growth issues that have to be solved along the way to reach the performance of the materials. The research has shown to be a fruitful foundation for new research collaborations, and expanding networks. The variety of SiC polytypes provides an interesting platform that could be applied for studying optoelectronic properties and crystal growth. The white LED is based on fluorescent SiC, and has no need for rare earth metals, and is less sensitive to the droop effect. By a combination of a layer doped with nitrogen and boron, together with a second layer doped with nitrogen and aluminum, the structure can provide a pure white light. In the SiC family, the cubic SiC is challenging to control in growth. We will describe a method for stabilization of the cubic SiC, and a way to provide free standing substrates. Boron doped cubic silicon carbide matches the model for intermediate bandgap solar cell material. The preliminary results will be presented.