Super-capacitive capabilities of wafer-scaled two-dimensional SnO2-Ga2O3 n-p heterostructures fabricated by atomic layer deposition

Two-dimensional (2D) conformal SnO2-Ga2O3 n-p heterostructures were fabricated on a wafer scale for the first time by atomic layer deposition (ALD) technique and their physicochemical properties as well as electrochemical behaviors as supercapacitor electrodes were subsequently investigated. High specific capacitance of 167 F g-1 was achieved at the current density of 7.69 A g-1 after annealing SnO2-Ga2O3 n-p heterostructures at 250 degrees C for 1 h in air. Moreover, sub-10 nm thick n-p heterostructures demonstrated high capacitance retention (-92.55 %) even after 10,000 continuous cycles. These findings are primarily attributed to the development of ultra-thin 2D SnO2-Ga2O3 heterostructures with high crystallinity, enabling fast charge transport through n-p heterojunctions. The results obtained could pay the way for the development of high-performance energy storage devices.