Cavity Design and Optimization for Organic Microcavity OLEDs

We report on detailed simulations of the emission from microcavity OLEDs consisting of widely used organic materials, n,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB) as a hole transport layer and tris (8-hydroxyquinoline) (Alq3) as emitting and electron transporting layer. The thick silver film was considered as a top mirror, while silver or copper films on quartz substrate were considered as bottom mirrors. The electroluminescence emission spectra, electric field distribution inside the device, carrier density and recombination rate were calculated as a function of the position of the emission layer, i.e. interface between NPB and Alq3. In order to achieve optimum emission from a microcavity OLED, it is necessary to align the position of the recombination region with the antinode of the standing wave inside the cavity. Once the optimum structure has been determined, the microcavity OLED devices were fabricated and characterized. The experimental results have been compared to the simulations and the influence of the emission region width and position on the performance of microcavity OLEDs was discussed

Arriving at a Unified Model for Hot-Carrier Degradation in MOSFETs Through Gate-to-Drain Capacitance Measurement

Hot carrier degradation of sub-micron n-channel and p-channel MOSFET’s from a CMOS process was investigated using small-signal gate-to-drain capacitance and charge pumping measurements for three different stress conditions. For both devices the worst case degradation was found to be due to the trapping of majority carriers and the creation of acceptor interface states, mainly in the upper half of the bandgap. It was concluded that the trapping of carriers and generation of interface states are separate processes. The effect of the donor interface states in the lower half of the bandgap necessary to associate the interface states with the pbo dangling bond model was not observed. A possible cause is suggested

Determination of carrier generation lifetime via current transient in MOS capacitor

A technique for the measurement of semiconductor minority carrier generation lifetime based on MOS capacitor current transient is presented. The lifetime is extracted by fitting a derived analytical model of the current transient to the experimental data. Values of lifetime obtained by this technique is shown to agree well with conventional capacitance transient method. 2-D numerical simulation to verify the method is also presented

Improvement in OFF-State Leakage Current of n-Channel SOS MOSFETs by Hydrogen Annealing of the SOS Film

The OFF-state source-to-drain leakage current and punchthrough voltage are the quantities that frequently limit the performance of short-channel floating-body silicon-on-sapphire (SOS) n-channel MOSFETs. In this paper, we demonstrate that the high-temperature hydrogen annealing of the SOS film prior to the device fabrication leads to marked improvement in these two parameters. The effect is attributed to the impact of hydrogen on the out-diffused thin alumina layer formed at the silicon-sapphire interface during the anneal. The thin alumina layer acting as a p-type dopant source at the back interface eliminates the back surface depletion of SOS n-MOSFETs. It also acts as a recombination center to eliminate the floating-body effect of floating-body n-MOSFETs. This technique provides a practical and reliable process to build short-channel floating-body SOS n-MOSFETs with OFF-state leakage as low as the junction leakage and punchthrough voltage as high as 6 V or higher at the gate length of 0.5 mu m without any degradation on the inversion layer carrier mobility or increase in the junction leakage current

Singaporeans’ attitudes toward lesbians and gay men, and tolerance toward media portrayals of homosexuality

Addressing the paucity of Asian literature on homosexual-related issues, this study investigates Singaporeans’ attitudes toward lesbians and gay men and their tolerance toward media portrayals of homosexuality. Besides documenting current public opinion in Singapore, this study also provides greater theoretical understanding by examining Asian values, religiosity and demographic factors as predictors of people’s attitudes toward lesbians and gay men and tolerance toward media portrayals of homosexuality.Bachelor of Communication Studie