Culturally diverse teams may require more central coordination than others

But there is such a thing as too much centralisation, find Christian Tröster, Ajay Mehra and Daan van Knippenber

Nationality Heterogeneity and Interpersonal Relationships at Work

In this dissertation I test three new approaches to extend the ‘classical’ model of workplace diversity. The ‘classical’ model of workplace diversity assumes that diversity affects work outcomes via the mediating effects of social networks. I hypothesize that this model fruitfully can be extended by 1) considering that diversity forms a context in which employees act, 2) testing alternative predictors of network formation and employee behavior (i.e., employee voice), and 3) integrating diversity and social network perspectives in a contingency model. Three empirical studies support these hypotheses. In the first study, I show that the association between leadership and employee voice is stronger for nationality dissimilar employees. The second study finds that employee voice affects the strength of friendship relations but that this effect is contingent on employees’ past position in the social network. Finally, the third study demonstrates that group performance is maximized at moderate levels of task network centralization but lowest at high and low levels of centralization but that this relation is moderated by nationality diversity. Nationality diverse teams required more centralization to achieve high performance than homogeneous teams. Finally, I discuss the implications of these findings for research on diversity and social networks

Contact resistance and overlapping capacitance in flexible sub-micron long oxide thin-film transistors for above 100 MHz operation

In recent years new forms of electronic devices such as electronic papers, flexible displays, epidermal sensors, and smart textiles have become reality. Thin-film transistors (TFTs) are the basic blocks of the circuits used in such devices and need to operate above 100 MHz to efficiently treat signals in RF systems and address pixels in high resolution displays. Beyond the choice of the semiconductor, i.e., silicon, graphene, organics, or amorphous oxides, the junctionless nature of TFTs and its geometry imply some limitations which become evident and important in devices with scaled channel length. Furthermore, the mechanical instability of flexible substrates limits the feature size of flexible TFTs. Contact resistance and overlapping capacitance are two parasitic effects which limit the transit frequency of transistors. They are often considered independent, while a deeper analysis of TFTs geometry imposes to handle them together; in fact, they both depend on the overlapping length (LOV) between source/drain and the gate contacts. Here, we conduct a quantitative analysis based on a large number of flexible ultra-scaled IGZO TFTs. Devices with three different values of overlap length and channel length down to 0.5 μm are fabricated to experimentally investigate the scaling behavior of the transit frequency. Contact resistance and overlapping capacitance depend in opposite ways on LOV. These findings establish routes for the optimization of the dimension of source/drain contact pads and suggest design guidelines to achieve megahertz operation in flexible IGZO TFTs and circuits

Oxide thin-film transistors on fibers for smart textiles

Smart textiles promise to have a significant impact on future wearable devices. Among the different approaches to combine electronic functionality and fabrics, the fabrication of active fibers results in the most unobtrusive integration and optimal compatibility between electronics and textile manufacturing equipment. The fabrication of electronic devices, in particular transistors on heavily curved, temperature sensitive, and rough textiles fibers is not easily achievable using standard clean room technologies. Hence, we evaluated different fabrication techniques and multiple fibers made from polymers, cotton, metal and glass exhibiting diameters down to 125 µm. The benchmarked techniques include the direct fabrication of thin-film structures using a low temperature shadow mask process, and the transfer of thin-film transistors (TFTs) fabricated on a thin (≈1 µm) flexible polymer membrane. Both approaches enable the fabrication of working devices, in particular the transfer method results in fully functional transistor fibers, with an on-off current ratio >107 , a threshold voltage of ≈0.8 V, and a field effect mobility exceeding 7 cm2 V −1 s −1 . Finally, the most promising fabrication approach is used to integrate a commercial nylon fiber functionalized with InGaZnO TFTs into a woven textile

Oxide thin-film electronics on carbon fiber reinforced polymer composite

In this letter, the direct fabrication of amorphous indium-gallium-zinc-oxide thin-film transistors (TFTs) and circuits on a commercial carbon fiber reinforced polymer (CFRP) substrate is demonstrated. The CFRP is encapsulated with a ≈10.6−μm -thick resin layer, although the surface roughness and temperature sensitivity of the substrate are not ideal for the fabrication of electronic devices, we present depletion mode TFTs exhibiting a field effect mobility of 18.3 cm2V−1s−1 , and a common source amplifier, providing a voltage gain of 8 dB and a −3 dB cutoff frequency of 11.5 kHz. The amplifier does not require any input bias voltage and can, hence, be directly used to condition signals originating from various transducers, e.g., piezoelectric strain sensors used to monitor the structural integrity of CFRP elements. This opens the way to the fabrication of smart mechanical CFRP parts with integrated structural integrity monitoring system

Positive charge trapping phenomenon in n-channel thin-film transistors with amorphous alumina gate insulators

No description supplie

Buckled Thin-Film Transistors and circuits on soft elastomers for stretchable electronics

Although recent progress in the field of flexible electronics has allowed the realization of biocompatible and conformable electronics, systematic approaches which combine high bendability ( 3-4 %) and low complexity in the fabrication process are still missing. Here, we show a technique to induce randomly-oriented and customized wrinkles on the surface of a biocompatible elastomeric substrate, where Thin-Film Transistors (TFTs) and circuits (inverter and logic NAND gates) based on Amorphous-IGZO are fabricated. By tuning the wavelength and the amplitude of the wrinkles, the devices are fully operational while bent to 13 µm bending radii as well as while stretched up to 5%, keeping unchanged electrical properties. Moreover, a flexible rectifier is also realized, showing no degradation in the performances while flat or wrapped on an artificial human wrist. As proof of concept, transparent TFTs are also fabricated, presenting comparable electrical performances to the non-transparent ones. The extension of the buckling approach from our TFTs to circuits demonstrates the scalability of the process, prospecting applications in wireless stretchable electronics to be worn or implanted

Entirely flexible on-site conditioned magnetic sensorics

The first entirely flexible integrated magnetic field sensor system is realized consisting of a flexible giant magnetoresistive bridge on‐site conditioned using high‐performance IGZO‐based readout electronics. The system outperforms commercial fully integrated rigid magnetic sensors by at least one order of magnitude, whereas all components stay fully functional when bend to a radius of 5 mm