In the present work, the influence of the molybdenum trioxide (MoO3) /N,N–Bis(3-methylphenyl)-N,N–bis(phenyl) benzidine(TPD)-like diamine multiple quantum well (MQW) structures as a hole injection layer (HIL)/hole transport layer (HTL) on the performance of organic light emitting diodes(OLEDs) has been studied. These devices have been attracted intensively due to their importance for using in fabrication of displays and solid state lightning and their interesting properties such as the lower voltage for operation, lower power utilization for light emission, clarification, inexpensiveness and lightness. The obtained results show that by using the MQW structures, the current density, luminance, current efficiency, power efficiency and electroluminescence (EL) spectra intensity of OLEDs is enhanced with respect to the simple device (SD). In MQW devices, the difference between Fermi level of indium tin oxide (ITO) (4.7 eV) and HOMO level of TPD (5.4 eV), leads to the reduction of driving and operating voltage. This finding indicates an enhancement of the hole injection and can therefore be used for the future of OLED devices.
