Photovoltaic device characterization with optical second harmonic generation

Optical second harmonic generation (SHG) has a long history of being used to selectively characterize surfaces and interface in a variety of materials, including semiconductors. Here, we briefly summarize the physics of SHG and explain why it is a promising characterization technique for photovoltaics (PV), where interfaces and surfaces play critical roles in device performance. We then show experimental results of initial SHG measurements performed on silicon heterojunction solar cells as they are swept through current-voltage curves.