Highly Efficient Trilayered White Quantum Dot Light Emitting Diodes Based on Organic Buffer Layers

We demonstrate highly efficient white quantum dot light emitting diode (QLED) devices using three separate quantum dots emission layers. The three luminescent layers are separated by two poly(p-phenylene benzobisoxazole) precursor buffer layers. These organic buffer layers have high lowest unoccupied molecular orbital levels, which contributes to the blocking of extra electrons and the balance of hole and electron injection. The developed trilayered white QLED device with organic buffer exhibits a high external quantum efficiency of 9.6 %, 16.4 cd/A in current efficiency, and a bright luminance of 4245.3 cd/m(2).