Sputtered-Growth of High-Temperature Seed-Layer Assisted β-Ga2O3 Thin Film on Silicon-Substrate for Cost-Effective Solar-Blind Photodetector Application

Abstract

β-Ga2O3 thin films was grown on cost-effective p-Si(100) substrate by sputtering technique. The evolution of crystalline structure with growth parameters revealed that the gallium oxide thin film grown on the high-temperature seed layer and various optimised growth parameters like sputtering power, deposition pressure and pre-substrate annealing has been proved extremely beneficial in exhibiting excellent crystalline quality. However, the direct growth of β-Ga2O3 on Si substrate with seed-layer was found to be amorphous in nature. The discussion about the critical role of varied growth conditions were carried in detail. The photoresponse of the optimized device showed a photoresponsivity of 95.64 AW−1 and a corresponding quantum efficiency of 4.73 × 104% at moderate bias under 250 nm illumination which is higher than most of the devices being reported on planar β-Ga2O3 solar-blind photodetectors deposited on high cost substrates. Moreover, the device showed the high transient response at moderate as well as at self-bias mode with good reproducibility and stability. The rise and decay time of the photodetector at self-powered mode was found to be in millisecond (58.3 ms/34.7 ms). This work paves the alternative way towards the fabrication of β-Ga2O3 solar-blind photodetector on cost-effective substrate and compatible with mature Si technology.