Our recent 2018 Nature Photonics paper shows how surface passivation can allow record carrier lifetimes, and achieve over 97% of the theoretical quasi-Fermi-level splitting (voltage) measured in the archetypal perovskite, methylammonium lead triiodide. Congratulations to Dane and Ian for a great paper and fruitful collaboration. Nature Photonics volume 12, pages355–361 (2018) DOI: 10.1038/s41566-018-0154-z