Optoelectronic characteristics of polymer light emitting diodes with poly(2-methoxy-5-(2′ethyl-hexoxy)-1,4-phenylene-vinylene) and hydrogenated amorphous silicon alloy heterointerfaces

In order to investigate the feasibility of combining polymer and inorganic films for light-emitting diode (LED) fabrication, the inorganic p-amorphous-Si:H/n-amorphous-SiCGe:H layer was employed as hole/electron injection layer (HIL/EIL) in the poly(2-methoxy-5-(2′ ethylhexoxy)-1,4-phenylene-vinylene) polymer LEDs (PLEDs). In contrast to the PLED without any amorphous HIL/EIL, which had an electroluminescence (EL) threshold voltage (Vth) of 10 V and a brightness of 1231 cd/m2 at an injected current density (J)=0.6 A/cm2, the EL Vth could be reduced to 6.9 V for PLED with a 6 nm p-a-Si:H HIL only, also, the brightness could be enhanced to 6450 cd/m2 (at J=0.3 A/cm2 only) for PLED with both p-amorphous-Si:H HIL and n-a-SiCGe:H EIL.