Correlation between O/Er content ratio and photoluminescence intensity of (Er, O)-doped hydrogenated amorphous Si thin films prepared by a catalytic chemical vapor deposition/laser ablation hybrid process

(Er, O)-doped hydrogenated amorphous Si (a-Si:H) thin films were prepared on Si or SiO₂ substrates by a novel catalytic chemical vapor deposition (Cat-CVD)/laser ablation hybrid process which simultaneously performs a Cat-CVD of a-Si:H matrices and a doping of laser-ablated (Er, O) from an Er₂O₃ sintered target. These (Er, O)-doped a-Si:H films showed excellent photoluminescence (PL) properties in spite of the low temperature of the process (200°C during deposition and no postannealing). The Er and O contents of these films were evaluated by Rutherford backscattering and non-Rutherford elastic resonance scattering (NRERS), respectively. It was clarified that the dependence of the (Er, O) content on ambient pressure was not identical for O and Er. Thus, the O/Er content ratio, correlated to the PL intensity, strongly depended on the ambient pressure.