We introduce a powerful, large-area self-assembly technique for orienting colloidal quantum wells in all face-down configuration. We demonstrate three-dimensional constructs of such oriented self-assemblies with monolayer precision. We present the most recent examples of LEDs and lasers using these oriented assemblies for lighting and displays. Here we also show record high efficiency from their LEDs and record thin gain medium from their laser structures. These solution-processed quantum wells hold great promise to challenge their epitaxial thin-film counterparts in semiconductor optoelectronics. © 2023, META Conference. All rights reserved.