We developed a promising deposition method for fabricating controllable layer-by-layer (LbL) quantum-dot (QD) structures. We introduced a spray coating method to induce desired properties of QD thin films as well as to control the thickness of QD layers. An intermediate heat treatment was applied between spray pass cycles to induce rapid evaporation of the surface ligands and solvent in the QD solution, which successfully prevents the formation of clusters on spray-coated QD (Sr-QD) films. Furthermore, we observed that the LbL structure of Sr-QDs has fewer surface defects and better crystallinity, leading to improved performance of optoelectronic devices compared to conventional solution-processed devices. Thus, our study suggests that this spray coating process enables detailed control of the properties and thickness of the QD films due to the highly controllable LbL structure of QD monolayers (MLs).