Vertically integrated multispectral imaging sensor with graphene as electrode and diffusion barrier

A method of fabricating a vertically integrated multispectral imaging sensor, comprising the steps of:

• depositing a first metal contact layer on a substrate and patterning the first metal contact layer;
• depositing an SiO2 layer over the substrate and first metal contact layer, and patterning the SiO2 layer to form a hole that exposes the first metal contact layer in approximately the center of the substrate;
• depositing a first detector material in the hole;
• transferring a graphene layer onto the SiO2 layer and patterning the graphene layer to form a first graphene layer that covers the first detector material;
• depositing and patterning a second metal layer on the SiO2 layer, wherein the second metal layer is adjacent to and makes contact with the first graphene layer;
• depositing an AlO3 layer over the SiO2 layer, wherein no AlO3 accumulates on the first graphene layer to form a hole that surrounds the first graphene layer;
• depositing a second detector material in the hole on the first graphene layer;
• transferring another graphene layer onto the AlO3 layer and the second detector material and patterning the graphene layer to form a second graphene layer that covers the second detector material;
• and
• depositing and patterning a third metal layer on the AlO3 layer wherein the third metal layer is adjacent to and makes contact with the second graphene layer,
• wherein the first detector material is sensitive to a different wavelength band of the electromagnetic spectrum than the second detector material.