With the daily mean concentrations of atmospheric carbon dioxide having reached 400 parts-per-million for the first time in human history, the need for carbon-neutral alternatives to fossil fuel energy has never been more compelling. With enough energy in one hour’s worth of global sunlight to meet all human needs for a year, solar technologies are an ideal solution. However, a major challenge is to develop efficient ways to convert solar energy into electrochemical energy on a massive-scale. A key to meeting this challenge may lie in the ability to test such energy conversion schemes on the micro-scale. . . .