Organic light-emitting diodes(OLEDs)with multiple-quantum-well structures,which consist of acromatic diamine and bathocuproine have been fabricated.The structure of the device is ITO/[NPB/BCP]n/AlQ/LiF/Al.The effect of the multiple-quantum-well(MQW)structure on the performance of OLEDs with tris(8-hydroxyquinoline)aluminum as the emitting material has been investigated.The emitting zone can be changed with the number of MQW.The maximum brightness of white emitting device reaches 3 433.8 cd/m2.The luminous efficiency is 2.26 cd/A at the current density of 60.9 mA/cm2.The brightness of the diode with the MQW number of 5 has been reached 866 1.0 cd/m2 with respect to 2 512.8 cd/m2 of the conventional green emitting diode without the MQW structure(ITO/NPB/AlQ/LiF/Al).The highest luminous efficiency is 4.94 cd/A at the current density of 20 mA/cm2.Such an improvement in the device performance should be attributed to the improved hole-electron balance,which can be further attributed to the introduction of the MQW structure.