Time-resolved study on the impact excitation and quenching processes of the 1.54 μm electroluminescence emission of Er ions in InP

Time-resolved impact excitation and de-excitation processes of the 1.54 μm electroluminescence (EL) emission of Er³⁺-doped InP are investigated. Samples are impact excited by applying electrical pulses and the time response of the EL emission is measured in the temperature range from 77 K to 330 K. The decay of the emission proves almost exponential in all the temperature ranges and shows little thermal quenching with the decay time decreasing from 2 ms at 77 K to only 1 ms at 330 K. This result contrasts with the large thermal quenching and nonexponential characteristics of the photoluminescence (PL) time decay at high temperatures in the same sample, suggesting different excited Er³⁺ centers between EL and PL. Also measured is the emission rise time as a function of excitation pulse current, giving us the impact cross section of 9×10^-16 cm² for Er³⁺ ions in InP. The excitation and quenching processes as well as the efficiency of Er emission are analyzed. A model taking into consideration the presence of different Er centers explains the different behaviors in the time responses between EL and PL.