Design and fabrication of a series contact RF MEMS switch with a novel top electrode

Radio-frequency(RF)micro-electro-mechanical-system(MEMS)switches are widely used in communication devices and test instruments.In this paper,we demonstrate the structural design and optimization of a novel RF MEMS switch with a straight top electrode.The insertion loss,isolation,actuator voltage,and stress distribution of the switch are optimized and explored simultaneously by HFSS and COMSOL software,taking into account both its RF and mechanical properties.Based on the optimized results,a switch was fabricated by a micromachining process compatible with conventional IC processes.The RF performance in the DC to 18 GHz range was measured with a vector network analyzer,showing isolation of more than 21.28 dB over the entire operating frequency range.Moreover,the required actuation voltage was about 9.9 V,and the switching time was approximately 33μs.A maximum lifetime of 109 switching cycles was obtained.Additionally,the dimension of the sample is 1.8 mm×1.8 mm×0.3 mm,which might find application in the current stage.

Efficiency Improvement of 590 nm AIGalnP Light Emitting Diode with a Reflective Top Electrode

In this work, enhancement of the light extraction efficiency of a 590 nm AIGaInP light-emitting diodes （LED） with a reflective top electrode （RTE） was investigated. A distributed Bragg reflector （DBR）, consisting of AIAs/AIGaAs pairs, grown on an AlGaInP structure was used as a reflector for a reflective top electrode. It was found that a higher output power was observed from the AIGalnP LED with a RTE than from a conventional one. In addition, it was noted that the improvement in the output power depends strongly on the reflectivity of the reflector and that it exhibits a more effective performance with low injection currents. The increase in the optical output power was attributed to the enhanced extraction efficiency caused by a reduction of light absorbed from the emission region to top electrode through the RTE.

Enhanced charge collection of AgNWs-based top electrode to realize high-performance,all-solution processed organic solar cells

All-solution processed organic solar cells are the ultimate aim of printable photovoltaics,but their electrical losses arising from poor contact of top electrodes greatly limit efficiency improvement.To solve the problem,a solution-processed hybrid top electrode was constructed using silver nanowires(AgNWs)as the skeleton and ZnO nanoparticles(ZnO-NPs)as the matrix.When constructing the skeleton,a spin-rinsing treatment was first used to reduce the amount of the residual insulating polyvinylpyrrolidone wrapped around the AgNWs to promote intimate contact among the AgNWs in the skeleton.Then,the ZnO-NPs matrix was deposited onto the AgNWs skeleton,bridging the AgNWs skeleton with the underlayer ZnO-NPs electron transporting layer(ETL).The underlayer ZnO-NPs ETL can also induce the growth of the ZnO-NPs matrix to minimize lattice mismatch,which creates additional transport channels from the ETL to the AgNWs skeleton for charge collection.As a result,the obtained electrode significantly enhances the electrical contact in the device,thus delivering record power conversion efficiencies of 16.04%and 14.54%for rigid and flexible all-solution processed OSCs,respectively.