(Invited) Modeling and Characterizing Defects in Semiconductors for Photovoltaics

Abstract

Photovoltaics are minority carrier devices and highly impacted by semiconductor defects. Furthermore the materials often must be synthesized at high rates using inexpensive processing. The result is that many solar cell technologies are produced from highly defective polycrystalline materials. This talk describes the use of a variety of techniques to study and model defects and the stability of the materials in a variety of semiconductors including Si, CdTe, (Ag,Cu)(In,Ga)Se2, and the hybrid perovskites. Examples include the use of x-ray photoelectron spectroscopy to study degradation in a hybrid perovskite, capacitance and scanning probe techniques to study defects in (Ag,Cu)(In,Ga)Se2 and CdTe, and modeling to understand defects in TiO2 in photoelectrochemical cells. The talk will also include a brief review of the state of photovoltaic technology, the energy generation technology currently being installed at the highest net rate in the U.S., how it interfaces with other technologies such as batteries, and the challenges and opportunities related to continued expansion of PV in our energy infrastructure.