This IRG explores how heterojunctions consisting of nanoelectronic materials of differing dimensionality are influenced by dielectric screening, electronic band/level offsets, and interfacial regions. By utilizing low-dimensional materials synthesis, surface chemical functionalization, spatially and spectrally resolved characterization, and advanced computation, IRG-1 develops quantitative descriptions of the nonlinear responses in mixed-dimensional heterojunctions. Elucidation of the mechanisms governing structural changes, and the corresponding changes in optoelectronic properties, allows controllable reconfiguration in response to stimuli including electric fields, photons, heating, and reactive species with implications for neuromorphic computing.