Event

The conventional device to convert light to electrical current uses two different kinds of doped silicon merged together known as pn junction or heterostructures. The current only flows one way in the pn junction due to a built-in electric field. Fabricating such heterostructures requires sophisticated thin film deposition methods. In contrast, the bulk photovoltaic effect, also called the photogalvanic effect, describes the electric current generation in a homogeneous material under light illumination. I will describe the quantum mechanical mechanism of the photogalvanic effect,  how it is different from the conventional pn junction in solar cells, and why it could be used to reach a higher energy conversion efficiency. Then I will also show two examples of new photo-galvanic effects from Weyl fermions in solids and in magnetic materials.