Harmonious Contact: Stories About Intergroup Musical Collaboration Improve Intergroup Attitudes

Watching contact between members of one's ingroup and members of an outgroup in the media (mediated vicarious contact) improves intergroup attitudes. We compare mediated vicarious contact with observing only members of the outgroup (parasocial contact), and examine whether the activity of the portrayed contact matters. Building on theory, we predict that watching outgroup members playing music should reduce prejudice more than watching them engaged in nonmusical activities, particularly with vicarious (vs. parasocial) contact. Results show that vicarious musical contact enhances perceptions of synchronization, liking, and honesty between ingroup and outgroup actors in a video, which in turn results in more positive attitudes toward the outgroup. Counter to predictions, parasocial musical contact results in less positive outcomes than parasocial nonmusical contact.     

Bridging Segregation Via Media Exposure? Ingroup Identification,Outgroup Distance,and Low Direct Contact Reduce Outgroup Appearance in Media Repertoires

Researchers have started to demonstrate that media exposure to outgroups can reduce prejudice. However, in contexts of segregation a bias to select ingroup-rich media might hinder exposure and prevent those positive effects. We conducted a survey study (n = 1,095) in South Africa, a context with a notorious history of racial separation and persisting informal segregation. In accordance with the social identity gratification approach and social cognitive theory, respondents showed group-related selection biases. Respondents who identified more strongly with their ingroup, who perceived more distance towards outgroups, and who had less direct contact showed stronger biases. The findings remind us that those who would potentially benefit the most from outgroup exposure might also be those who are least likely to be exposed.     

Reliance on Direct and Mediated Contact and Public Policies Supporting Outgroup Harm

Two studies examined the effects of reliance on direct and media‐based contact for information about Muslims on Americans' stereotypic beliefs of and negative emotions toward Muslims and support for public policies harming Muslims domestically and internationally. Results revealed that reliance on media for information about Muslims was positively associated with stereotypic beliefs, negative emotions, and support for harmful policies. Reliance on direct contact for information about Muslims produced the opposite results. Results from a three‐wave longitudinal design revealed that reliance on media and direct contact significantly predict changes in negative emotions which then predict changes in support for civil restrictions for Muslim Americans. We discuss the differential effects of reliance on media‐based and direct contact in influencing intergroup outcomes.     

How small the contacts could be optimal for nanoscale organic transistors?

We report on a study seeking an optimized contact configuration for organic transistors that minimizes contact effects but maintains smallest contact size. We begin with the bulk access resistance in staggered transistors which results from the charge transport through the organic semiconductor film. Bulk access resistance is an intrinsic contributor to the contact resistance which has been little understood due to lack of a reliable study tool. In this work, we utilize the inner transported power inside the semiconductor film as a medium to investigate the contact resistance and the relevant contact effects. We examine the influences of the organic film thickness (t_SC), the channel length (L), the underlying charge transport and various organic semiconductor materials with variable carrier mobility. A roughly optimal contact length (L_C) of L_C0 ≈ 6t_SC is obtained. The results reveal that besides the device architecture the underlying charge transport should be also taken into account in designing organic transistors for practical application.     

Prediction of sessile drop evaporation considering surface wettability

Previous studies suggest that most theoretical models for drop evaporation based on an ideally simplified domain in which evaporation occurs do not correlate well with experimental results. The present paper proposes a novel empirical model f(θ) as a simple function of the contact angle θ, which is to be used to predict temporal evolution of a sessile water drop volume when the drop evaporates on surfaces of various wettabilities widely adopted in microelectronic engineering. For hydrophilic and hydrophobic surfaces, the evolution of the drop volume during the evaporation process can be predicted more accurately by representing f(θ) as an empirical linear function rather than by using previous theoretical models. Furthermore, the proposed model can account for the increased evaporation rate on smooth surfaces, thus providing a wide applicability to various substrate surfaces. For cases involving a superhydrophobic surface, f(θ) can be represented by an empirical constant because the contact angle remains constant during evaporation, which is in excellent agreement with the experimental observation.     

Analysis of contact effects in fully printed p-channel organic thin film transistors

Contact effects have been analyzed in fully printed p-channel OTFTs based on a pentacene derivative as organic semiconductor and with Au source–drain contacts. In these devices, contact effects lead to an apparent decrease of the field effect mobility with decreasing L and to a failure of the gradual channel approximation (GCA) in reproducing the output characteristics. Experimental data have been reproduced by two-dimensional numerical simulations that included a Schottky barrier (Φ_b = 0.46 eV) at both source and drain contacts and the effects of field-induced barrier lowering. The barrier lowering was found to be controlled by the Schottky effect for an electric field E < 10⁵ V/cm, while for higher electric fields we found a stronger barrier lowering presumably due to other field-enhanced mechanisms. The analysis of numerical simulation results showed that three different operating regimes of the device can be identified: (1) low |V_ds|, where the channel and the Schottky diodes at both source and drain behave as gate voltage dependent resistors and the partition between channel resistance and contact resistance depends upon the gate bias; (2) intermediate V_ds, where the device characteristics are dominated by the reverse biased diode at the source contact, and (3) high |V_ds|, where pinch-off of the channel occurs at the drain end and the transistor takes control of the current. We show that these three regimes are a general feature of the device characteristics when Schottky source and drain contacts are present, and therefore the same analysis could be extended to TFTs with different semiconductor active layers.     

Scaling limits of organic digital circuits

The effect of device scaling on organic circuits’ performance was studied. Particularly, the influence of contact resistance on the static and the dynamic behavior of the circuits was investigated. For that purpose, an analytical model describing the voltage transfer characteristics (VTCs) and the propagation delay was developed. Using the model, it was shown that for OTFTs with channel lengths of less than 10 μm the contact resistance has negative influence on both, the static noise margin (SNM) and the propagation delay. Moreover, the model is in a good agreement with experimentally measured data. Scaling the lateral dimensions of the transistors down to few μm limits the circuit performance due to contact effects, and the 1–10 MHz frequency range operation required by some applications can only be achieved by reducing the specific contact resistance, ρ_c, 10–100 times. This need for ρ_c reduction highlights the importance of improving charge injection in organic transistors that can usually be achieved by contact doping like in inorganic electronics.     

Characterization of organic thin film transistors with hysteresis and contact effects

We propose two procedures to extract information about the trapping processes that occur in organic thin film transistors (OTFTs) that exhibit both contact and hysteresis effects. In particular, the variation of trapped charge during hysteresis cycles is determined by the separate analysis of current–voltage curves for the intrinsic transistor and for the contact region. The extraction of these curves is done with the help of our previous compact model that reproduces the current–voltage characteristics of OTFTs with contact effects. The model is used to fit experimental output characteristics with hysteresis and to extract the parameters of the model, such as the mobility and the threshold voltage. The variation of the threshold voltage with trapped charges during voltage cycling and using existing transistor models results in different sets of parameters needed to reproduce the experimental data. However, not all these parameters have proper physical meanings. In order to find a unique physical solution, the current–voltage curves of the contacts and current–voltage curves of the intrinsic transistor, extracted from the output characteristics measured at the transistor terminals, are separately analyzed. The study of the evolution with the gate voltage of the free-charge density in the contact allows for finding this unique solution. The results of this method are compared with published results that use more elaborate experimental techniques, such as the four-terminal method or transient experiments.     

Media as Educator,Media as Disruptor: Conceptualizing the Role of Social Context in Media Effects

We document how social contexts serve to refract media effects. We theorized the relationship between media use and individual‐level knowledge (and attitude) would be stronger when community‐level knowledge (and attitude) was low than when it was high. Data come from a national survey (N = 12,608 women and 1,237 men) conducted in Nepal. Knowledge and stigma toward people living with HIV were the 2 dependent variables. Hypotheses were tested 12 times: across the use of 3 media (newspaper, radio, television) × 2 study outcomes (knowledge and attitudes) × 2 genders. Predicted interactions were supported in 9 of the 12 tests. Findings point to the need to take into account the role of community factors in theorizing about media effects.     

Examining the Hostile Media Effect as an Intergroup Phenomenon: The Role of Ingroup Identification and Status

This approach conceptualizes the hostile media effect (HME) as an intergroup phenomenon. Two empirical studies, one quasi‐experimental and one experimental, examine the HME in the context of the abortion debate. Both studies show that ingroup identification and group status qualify the HME. Pro‐choice and pro‐life group members perceived an identical newspaper article as biased against their own viewpoint only if they considered their ingroup to have a lower status in society than the outgroup. In addition, only group members with a stronger ingroup identification showed a HME, particularly because of self‐investment components of ingroup identification. Taken together, the findings confirm the important influence of ingroup status and ingroup identification on the HME.     

The optimization of the double mask system to minimize the contact resistance of a Ti/Pt/Au contact

The fabrication of Ti/Pt/Au ohmic contacts on diamond using two transmission line model masks during the photolithography step was modified as a result of the adverse effects on the resistance from the rectifying lip created by the overlap of the two masks, and the possible inhibition of carbide formation due to the presence of oxygen on the diamond surface before metallization. The first modification consisted of decreasing the rectifying lip by diffusing a small amount of Ti from beneath the contact defined by the first mask, and decreasing the overlap of the two masks from 5 to 2 μm, which is close to the minimum allowable by our photolithography techniques. The second modification consisted of the desorption of oxygen from the diamond surface using a heat treatment in vacuum and cool down in purified hydrogen. As a result of these changes, the contact resistance was decreased by more than two orders of magnitude from 8.1 × 10^-2 Ω-cm² to 1.2 × 10^-4 Ω-cm².     

On the source of scatter in contact resistance data

Previous treatments have assumed that small fluctuations in contact window dimensions between devices are chiefly responsible for the scatter in contact resistance data. Although this is plausible, it is shown in this paper that the source of this scatter is variation in contact resistivity, ρ_c, from resistor to resistor. It is further suggested that ρ_c is Cauchy distributed. Since standard deviation is in theory infinite for a Cauchy distribution, very high values of resistance at a contact window would occur with much greater frequency than common sense might suggest.     

The Effects of Language Brokering Frequency and Feelings on Mexican‐Heritage Youth's Mental Health and Risky Behaviors

Language brokering is the communication process where individuals with no formal training (often children of immigrant families) linguistically mediate for 2 or more parties (usually adult family members and individuals from mainstream culture). This study examined the direct and indirect effects of language brokering on mental health and risky behaviors. Mexican‐heritage youth (N = 684) from schools in Phoenix, AZ, completed surveys at 3 waves from 7th through 8th grades. Language brokering frequency and negative brokering feelings were positively associated with family‐based acculturation stress, which was positively associated with alcohol use and other risky behaviors. Yet, brokering frequency was negatively associated with other risky behaviors, and positive brokering feeling was negatively associated with cigarette use. Implications for these findings are discussed.     

Beyond Cognitive Framing Processes: Anger Mediates the Effects of Responsibility Framing on the Preference for Punitive Measures

A new stream of research indicates that framing effects are based on emotional as well as cognitive processes. However, it is not entirely clear whether emotions mediate framing effects and what the moderators of emotional mediation processes are. To address these questions, we conducted an experiment in which the framing of responsibility for a social problem was manipulated (ambivalent vs. high‐responsibility frame). We find that the high‐responsibility frame increased the preference for punitive measures by increasing responsibility beliefs and eliciting anger. Furthermore, we find that trait anger moderates the framing effect on anger and that responsibility beliefs are positively associated with anger intensity. The significance of these findings for framing research and suggestions for future studies are discussed.     

Enhanced Performance of Fullerene n‐Channel Field‐Effect Transistors with Titanium Sub‐Oxide Injection Layer

Enhanced performance of n‐channel organic field‐effect transistors (OFETs) is demonstrated by introducing a titanium sub‐oxide (TiO_x) injection layer. The n‐channel OFETs utilize [6,6]‐phenyl‐C₆₁ butyric acid methyl ester (PC₆₁BM) or [6,6]‐phenyl‐C₇₁ butyric acid methyl ester (PC₇₁BM) as the semiconductor in the channel. With the TiO_x injection layer, the electron mobilities of PC₆₁BM and PC₇₁BM FET using Al as source/drain electrodes are comparable to those obtained from OFETs using Ca as the source/drain electrodes. Direct measurement of contact resistance (R_c) shows significantly decreased R_c values for FETs with the TiO_x layer. Ultraviolet photoelectron spectroscopy (UPS) studies demonstrate that the TiO_x layer reduces the electron injection barrier because of the relatively strong interfacial dipole of TiO_x. In addition to functioning as an electron injection layer that eliminates the contact resistance, the TiO_x layer acts as a passivation layer that prevents penetration of O₂ and H₂O; devices with the TiO_x injection layer exhibit a significant improvement in lifetime when exposed to air.     

A comparative study on a high aspect ratio contact hole etching in UFC- and PFC-containing plasmas

An etching of a SiO₂ contact hole with a diameter of 0.19 μm and an aspect ratio of 13, using C₄F₆/Ar/O₂/CH₂F₂ and c-C₄F₈/Ar/O₂/CH₂F₂ plasmas, was performed for a feasibility test of the use of unsaturated fluorocarbons (UFCs) as an alternative to perfluorocarbon (PFC) gases for a high aspect ratio contact hole etching. The etch profile of the contact hole obtained in the C₄F₆/Ar/O₂/CH₂F₂ plasma was shown to have 23% lower degree of bowing than that in the c-C₄F₈/Ar/O₂/CH₂F₂ plasma. The Kelvin and chain contact resistances of the contact holes etched in the C₄F₆/Ar/O₂/CH₂F₂ plasma were 10-12% higher than those in the c-C₄F₈/Ar/O₂/CH₂F₂ plasma, but they were within the device spec. The integration of device with 0.1 μm design rule using C₄F₆/Ar/O₂/CH₂F₂ and c-C₄F₈/Ar/O₂/CH₂F₂ plasmas during the contact hole etching was also conducted, and it was found that etch profiles, metal coverage, and bottom critical dimensions of the contact in the C₄F₆/Ar/O₂/CH₂F₂ plasma were nearly identical to those in the c-C₄F₈/Ar/O₂/CH₂F₂ plasma, suggesting that the use of C₄F₆ gas as an etchant gas for a high aspect ratio contact hole etching can be a good alternative to PFC gases.     

Young Voters' Responses to the 2004 U.S. Presidential Election: Social Identity,Perceived Media Influence,and Behavioral Outcomes

Hostile news perceptions, perceived media influence, and behavioral outcomes among Republicans and Democrats were examined before and after the 2004 U.S. presidential election. Predictions were grounded in social identity/self‐categorization theories, and influence of presumed influence. Hostile news perceptions were greater among Republicans, especially Fox News viewers. Third‐person perceptions (TPPs) for ingroup and outgroup (own party, other party) varied based on media message (debates, news, spin, polls, comedy) and party affiliation. TPPs were larger for the outgroup than the ingroup, but only for Republicans. Following the election, changes in media perceptions were related to the election outcome and interpersonal discussion. Greater perceived influence on outgroup voters was associated with stronger support for censorship, and a lower voting likelihood among Democrats.     

Contact-resistance effects in PDI8-CN2 n-type thin-film transistors investigated by Kelvin-probe potentiometry

In this paper, the metal-semiconductor contacts in n-type bottom-contact bottom-gate Organic Field-Effect Transistors (OFET), based on evaporated films of a perylene diimide derivative (PDI8-CN₂), have been investigated by Scanning Kelvin Probe Microscopy (SKPM). OFET were characterized for different thicknesses of the PDI8-CN₂ film and in the light of the gold electrode functionalization with an aromatic thiol self-assembled monolayer. SKPM experiments reveal that aromatic thiol functionalization produces a 30% reduction in the contact resistance (R_c), while lowering the organic film thickness, the contact resistance (R_c) phenomenon tends to be magnified. The experimental observation that the voltage drops occurring close the drain electrode are even larger than those taking place at the source contact suggests that it is not possible, for these devices, to explain the overall R_c effects by simply referring to the presence of a reverse-biased Schottky junction limiting the electron injection process into the active channel.     

Al contacts to nanoroughened p-GaN

Nanoroughening of a p-GaN surface using nanoscale Ni islands as an etch mask was utilized to investigate the feasibility for the flip-chip configuration light-emitting diodes (LEDs) using an Al-based reflector. Improved ohmic characteristics were found for the nanoroughened sample. A specific contact resistivity of 8.9×10⁻² Ω cm² and a reflectance of 82% at 460 nm were measured for the nanoroughened Al contact. The Schottky barrier heights were decreased from 0.81 eV (I-V) and 0.84 eV (Norde) for the Al contact to 0.70 eV (I-V) and 0.69 eV (Norde) for the nanoroughened Al contact. The barrier height reduction may be attributed to enhanced tunneling and the increased contact area due to the nanoroughening. This work suggests that the ohmic contact characteristics and the light extraction efficiency may be improved further with a well-defined nanopatterned p-GaN layer.     

Modeling the gate bias dependence of contact resistance in staggered polycrystalline organic thin film transistors

We have modeled the dependence on the gate voltage of the bulk contact resistance and interface contact resistance in staggered polycrystalline organic thin film transistors. In the specific, we have investigated how traps, at the grain boundaries of an organic semiconductor thin film layer placed between the metal electrode and the active layer, can contribute to the bulk contact resistance. In order to the take into account this contribution, within the frame of the grain boundary trapping model (GBTM), a model of the energy barrier E_B, which emerges between the accumulation layer at the organic semiconductor/insulator interface and injecting contact, has been proposed. Moreover, the lowering of the energy barrier at the contacts interface region has been included by considering the influence of the electric field generated by the accumulation layer on the injection of carriers at the source and on the collection of charges from the accumulation layer to the drain contact. This work outlines both a Schottky barrier lowering, determined by the accumulation layer opposite the source electrode, as well as a Poole-Frenkel mechanism determined by the electric field of the accumulation layer active at the drain contact region. Finally it is provided and tested an analytical equation of our model for the contact resistance, summarizing the Poole-Frenkel and Schottky barrier lowering contribution with the grain boundary trapping model.