High-brightness AlGaInP 573-nm light-emitting diode with a chirped multiquantum barrier

A novel chirped multiquantum barrier (CMQB) structure was used for AlGaInP light-emitting devices. We have theoretically studied the blocking efficiency of the CMQB structure and found that the CMQB structure is more effective in blocking the electron wave than the conventional uniform multiquantum barrier (UMQB) structure. AlGaInP light emitting diodes (LED's) with the CMQB structure and the UMQB structure were both fabricated and compared. It was found that the luminescence intensity of the AlGaInP CMQB LED is larger and the intensity distribution of the AlGaInP CMQB LED is more uniform than the AlGaInP UMQB LED. The intensity-current measurement also shows that the electroluminescence intensity of the AlGaInP CMQB LED starts to saturate at a higher injection current.