Effect of microstructures on the electrical and optoelectronic properties of nanocrystalline Ta–Si–N thin films by reactive magnetron cosputtering

The evolution of an amorphous-like to a polycrystalline microstructure and the composition of Ta–Si–N nanocomposites was controlled by nitrogen flow ratios during reactive cosputtering. It influences the chemical bonding, electrical resistivity and optoelectronic luminescent properties of Ta–Si–N films. Amorphous-like Ta–Si–N films formed at a Si/(Si + Ta) ratio larger than 6% had much finer grains, smoother morphology, lower Ta 4f7/2 binding energy and lower resistivity compared to polycrystalline films. A strong visible photoluminescence was observed at Ta53Si7N40 compositions for a peak maximum at 554 nm (2.24 eV).