Effects of transparent MPTMS/Ag/MoO₃ structure as anode on the performance of green organic light-emitting diodes

Abstract

A transparent 3-mercaptopropyl trimethoxysilane (MPTMS)/Ag/MoO₃ composite anode is introduced to fabricate green organic light-emitting diodes (OLEDs). Effects of the composite anode on brightness and operating voltage of OLEDs are researched. By optimizing the thickness of each layer of the MPTMS/Ag/MoO₃ structure, the transmittance of MPTMS/Ag (8 nm)/MoO₃ (30 nm) reaches over 75% at about 520 nm. The sheet resistance is 3.78 Ω/□, corresponding to this MPTMS/Ag (8 nm)/MoO₃ (30 nm) structure. For the OLEDs with the optimized anode, the maximum electroluminescence (EL) current efficiency reaches 4.5 cd/A, and the maximum brightness is 37 036 cd/m². Moreover, the OLEDs with the optimized anode exhibit a very low operating voltage (2.6 V) for obtaining brightness of 100 cd/m². We consider that the improved device performance is mainly attributed to the enhanced hole injection resulting from the reduced hole injection barrier height. Our results indicate that employing the MPTMS/Ag/MoO₃ as a composite anode can be a simple and promising technique in the fabrication of low-operating voltage and high-brightness OLEDs.

Keywords

Sheet Resistance / Hole Injection / Apply Physic Letter / Atomic Force Micro / Composite Anode

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