Influence of Er and O doses in Er-related emission in Al_0.70Ga_0.30As:Er

Abstract

Er ions with doses ranging from 1×10¹³ cm⁻² to 1×10¹⁵ cm⁻² were implanted into Al_0.70Ga_0.30As on GaAs substrates. at 800 °C. Photoluminescence (PL) intensity of Er-related emission around 1.54 μm was enhanced by co-implanted oxygen (O). The optimum dose of Er ion was 1×10¹⁴ cm⁻² and O ion was 1×10¹⁵ cm⁻², respectively. Furthermore, from the temperature dependence of the PL intensity of sample implanted with the optimum dose, we estimated the values of E₁, E₂, and E₃, the activation energies in order to investigate the rapid thermal quenching of Er ion in Al_0.70Ga_0.30As. We found that PL intensity of Er-related emission, in addition to O dose, was enhanced approximately twenty two times at room temperature. And from the temperature dependence of the lifetime of the optimum dose of Er and O, the value 245meV of E_A, the activation energy for the decrease of the lifetime, was nearly equal to the value 235meV of E₃. Based on the result, the decrease of the lifetime confirms that the radiative efficiency is lower; therefore, we propose that rapid thermal quenching occurs at temperatures above 200 K due to the decrease of the radiative efficiency.