LAUSR

Abstract We present a two-step facile method to prepare Ni2O3 coral–like and flower–like nanostructures first time followed by structural, optical characterizations by XRD, FESEM, HRTEM, Raman, luminescence spectroscopy etc. We also report rectifying I–V characteristics of Ni2O3 nanostructures/Al based metal–semiconductor junction with ultralow turn-on voltages (0.36 V), potential barrier (0.33 eV), very ideal thermionic current (η = 1.11). Photo-responsive character illustrates that the junction devices could be a promising material for light sensing application. Parameters like series resistance (111.4 Ω), electron mobility (16.73 × 10−10 m2V1s−1), diffusion length (5.13 × 10−7 m), density of states (3.09 × 1040 eVm−3) etc. have been evaluated and it is discussed that the defect (Ni3+ vacancy) induced electron–phonon interaction within the active semiconducting layer plays the crucial role to determine these parameters. Most importantly, it has been identified that the charge-transport across the junction follows non-adiabatic mechanism. Our results suggest a new insight into current transport mechanism that may be generalized to understand microstructural, defect dependence MS junctions.