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.