Strain effects on the optoelectronic performance of ultra-wide band gap polycrystalline β-Ga2O3 thin film grown on differently-oriented Silicon substrates for solar blind photodetector

β-Ga2O3 based photodetectors are being intensively researched as possible substitutes to conventional Silicon deep-UV PDs. However, high cost of single-crystalline Ga2O3 poses hindrance towards commercialization by semiconductor industry still monopolized by Si. An easier integration with existing technology can be achieved by growing Ga2O3 thin films on Si directly, but growth of lattice mismatched substrates is often tricky and complicated with various parameters such as interfacial energies, surface energies, etc. playing important roles. Thus, it becomes imperative to investigate the role of each of these on film growth and devices thereof. Herein, polycrystalline β-Ga2O3 thin films are grown on different orientations of Si namely (1 0 0), (1 1 0) and (1 1 1), offering varied surface energies for film growth even under identical conditions. Best growth is observed on Si (1 1 1) substrate, deduced by largest crystallite size and lowest strain using Williamson-Hall method. This leads to devices of Ga2O3 on Si (1 1 1) having improved performance compared to other orientations. To validate effect of strain on device performance, a well-known method of reducing strain further – introduction of seed layer – is utilized, leading to further enhancement. This implies that PD performance is highly dependent on orientation of substrate used as the strain induced ultimately affects film growth.