Designing wearable sensors or other devices demands robust, flexible electronics. Extremely thin films, just one atom thick, such as molybdenum disulfide (MoS2), hold promise. Large-area synthesis of these materials is required for their commercialization. But today’s thin films are plagued by structural defects. These defects degrade device performance. Scientists at New York University and the Center for Functional Nanomaterials have implemented a superacid treatment for healing defects in thin MoS2 films. They showed that this straightforward chemical treatment is compatible with electronic device fabrication. Also, the process boosts device performance by reducing the density of defects in the material.