Current silicon solar cell efficiencies are approaching the fundamental limit of 31%, motivating the need for innovative architectures that increase efficiency. I will discuss and demonstrate one such architecture, along with the transient absorption/reflection laser experiment that we’ve designed for its analysis. The architecture is designed to increase solar cell photocurrent by promoting impact ionization at the junction between two absorber layers. Through this heterojunction-assisted impact ionization, two free electrons are produced by the absorption of a single high-energy photon.