Generally, examples described herein relate to methods and processing chambers and systems for forming a stacked pixel structure using epitaxial growth processes and device structures formed thereby. In an example, a first sensor layer is epitaxially grown on a crystalline surface on a substrate. A first isolation structure is epitaxially grown on the first sensor layer. A second sensor layer is epitaxially grown on the first isolation structure. A second isolation structure is epitaxially grown on the second sensor layer. A third sensor layer is epitaxially grown on the second isolation structure.