The influence of thermal annealing to the characteristics of AlGaInP/GaInP multiple quantum wells light-emitting diode wafers

The influence of thermal annealing to the characteristics of AlGaInP/GaInP multiple quantum wells (MQWs) light-emitting diode wafers was studied by means of electrochemical capacitance-voltage (ECV) and photoluminescence (PL). Compared with the sample unannealed, the hole carrier concentration of p-GaP layer increased from 5.5×10¹⁸ to 6.5×10¹⁸ cm⁻³, and the hole carrier concentration of p-AlGaInP layer increased from 6.0×10¹⁷ to 1.1×10¹⁸ cm⁻³, after wafer was annealed at 460 °C for 15 min in nitrogen. The hole carrier concentrations of p-GaP layers and p-AlGaInP layers did not obviously change when the annealing temperature varied from 460 to 700 °C. However, after the sample was annealed under 780 °C for 15 min, the hole carrier concentration of p-GaP layer and p-AlGaInP layer decreased to 8×10¹⁷ and 1.7×10¹⁷ cm⁻³, respectively. At the same time, the diffusion of Mg atoms was observed.