Enhancement of organic light-emitting device performances  with Hf-doped indium tin oxide anodes

Chen, T.-H.; Liou, Y.; Wu, T. J.; Chen, J. Y.

doi:doi:10.1063/1.1790026

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Photoconductivity from PbS-nanocrystal∕semiconducting polymer composites for solution-processible, quantum-size tunable infrared photodetectors

We report photoconductivity at infrared wavelengths, 975–1300 nm, from a polymer∕nanocrystal quantum dot composite. Biased films of the conjugated polymer poly[2-methoxy-5-(2′-ethylhexyloxy-p-phenylenevinylene)] (MEH-PPV) sensitized with PbS nanocrystals (∼5 nm diameter) demonstrate photocurrent at wavelengths beyond the response of the polymer and corresponding to the absorption of the nanocrystals. The photocurrent is attributed to absorption in the nanocrystals with subsequent hole transfer t...

Nanoscale measurements of the absolute temperature from the tunneling of the free electron gas

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We have enhanced the luminance and the power efficiency of organic light-emitting devices with Hf-doped indium tin oxide (ITO) anodes instead of a CuPc layer. The Hf-doped ITO layer with a thickness of 15 nm was deposited on top of the ITO anode. Less than 10 mol. % of Hf was doped in ITO films by adjusting the sputtering rates of both sources. The highest work function of the Hf-doped ITO layers was 5.4 eV at the Hf concentrations about 10 mol. %. The driving voltages of the device have been reduced by 1 V. A luminance of 1000 cd∕m² at 7 mA∕cm², a current efficiency of 14 cd∕A, and a power efficiency of 6 lm∕W at 6 mA∕cm² have been achieved in the device with a 4 mol. % Hf-doped ITO layer (work function=5.2 eV). In general, the performance was about 50% better than the device with a CuPc buffer layer.