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Top-emitting organic light-emitting diodes (OLEDs) using aluminium (Al) and nickel (Ni) as the anode and Al as the semitransparent cathode were developed. Hole injection was largely improved by spin coating poly(ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT) on the metal anode. For top-emitting OLEDs with a configuration of metal anode/PEDOT/NPB/Alq3/LiF/Al/Alq3, both devices using Al and Al/Ni anodes showed efficient green light emission with a narrow emission peak. Current efficiency was increased from 4.32 cd A−1 to 6.45 cd A−1 when replacing high work function Ni with low work function Al as the anode. A luminance of 20 000 cd m−2 can be achieved for these top-emitting OLEDs. The device made with the Al/Ni anode showed a low driving voltage and high power efficiency as compared to that made with the Al anode. The improvement on light-emitting efficiency was attributed to balanced charge carrier injection and utilization of the high reflective semitransparent Al cathode.

Efficient electroluminescence (EL) was obtained from quinacridone (QA) sub-monolayer inserted in a tris(8-quinolinolato) aluminum (ALQ) layer which was confined by a blocking layer 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP). The thickness of the confined ALQ layer was optimized and the highest EL current efficiency of 7.2 cd/A was obtained by inserting a 0.02 nm-thick QA layer in the 10-nm thick ALQ layer, we attribute it to the narrow exciton formation zone, in which both electron and hole carriers were confined and resulted in efficient collision capture in the exciton formation process. In addition, exciton confinement led to improved energy transfer from ALQ to QA and weaken the emission from the ALQ itself. The two factors are simultaneously operating in efficiency enhancement.

Efficient electroluminescence (EL) was obtained in organic light-emitting devices (OLEDs) using a Quinacridone (QAD) sub-monolayer as emitter, which was inserted in a narrow excitons formation Alq 3 layer. For the structure-optimized devices, efficient QAD emission almost without Alq 3 EL was observed, and a highest efficiency of 7.2 cd/A was attained by inserting 0.02-nm-thick QAD layer in the middle of 10-nm-thick Alq 3 layer which neighbored a blocking layer 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP). The performance improvement was attributed to the application of the narrow excitons formation zone, in which both electrons and holes were confined, and resulted in efficient collision capture for the excitons formation. Confinement of excitons induces enhanced energy transfer from Alq 3 to QAD and weak emission from the Alq 3 .

Micromechanical optical switch has a good quality for free-space optical cross connects, particularly in terms of the low insertion loss, low crosstalk, low polarization dependent loss (PDL), wavelength-independence, and bit-rate transparency. In research of micromechanical optical switches, the electrostatic torsion beam actuator is widely used. But this actuator needs high-applied voltage. In this paper, the actuator with the slant counter electrode was proposed and fabricated with tilted 3° (111) silicon wafer.