We explore the assembly of quantum dots in new quantum-dot solids. These materials, assembled from solution-processable building blocks, hold great promise for new optoelectronic devices due to their ease of production, high tunability and flexibility. Because of their quantum confinement, quantum dots have distinct energy levels just like atoms, and their assembly into periodic structures leads to new energy bands, so-called “minibands”, analogues of bands and electronic states in solids. Contrary to atoms, this mini-band structure can be easily “designed” by the properties and mutual interaction of the building blocks. Yet, such design requires insight into the assembly of quantum dots, the role of surface chemistry in the coupling of the quantum dots, and the resulting optoelectronic properties.