After quickly achieving highly-efficient (>18%) metal halide perovskite PV devices in spring 2014, we immediately resolved to stabilize the perovskite material through better chemistry. Our early tests showed that even though our perovskite devices were highly-efficient and very reproducible, all the materials that made for an efficient device, also caused the PV device to fail. All these materials are still commonly used by our competitors, even today.  Based on our learnings, we are also exploring other applications incorporating our highly-stable and efficient perovskite semiconductor.