> we already have solar cells over this theoretical limit I need to ask my brother how this new method compares to his work[1] on high efficiency heterojunctio

> we already have solar cells over this theoretical limit I need to ask my brother how this new method compares to his work[1] on high efficiency heterojunction solar cells. While this is all really interesting physics, it quickly races past my electrical-engineering-level of understanding. (the apparatus he made to build these heterojunctions one-layer of atoms at a time (molecular beam epitaxy) was crazy; you're in the sci-fi future when your project needs a high-purity sapphire substrate and vacuum with a mean free path >10km) [1] (Lang) https://aip.scitation.org/doi/abs/10.1063/1.3575563 https://aip.scitation.org/doi/abs/10.1063/1.3575563