Heralding the end of a decade-long quest, in a promising new class of extremely thin, two-dimensional semiconductors, scientists have for the first time directly visualized and measured elusive particles, called dark excitons, that cannot be seen by light. The powerful technique, described in Science, could revolutionize research into two-dimensional semiconductors and excitons, with profound implications for future technological devices, from solar cells and LEDs to smartphones and lasers.
