The concept of general density of states (DOS) in devices is, by definition, spatially invariant. However, in the case of inhomogeneous materials or in quantum confined structures, the density of states can be resolved in space. This is known as local density of states, or LDOS.
The LDOS definition becomes particularly important in confined devices where quantum reflection causes spatial variation in the density of states. LDOS for a nanowire MOSFET is shown in this image. As the gate bias is increased, the confined energy levels are pushed down. The variation in density of states near the source is due to reflection from the potential barrier, and can also be seen.