Developing effective and low‐cost organic hole‐transporting materials (HTMs) is crucial for the construction of high‐performance perovskite solar cells (PSCs) and to promote their production in commercial ventures. In this context, we herein report the molecular design, synthesis and characterization of two novel D‐A‐D‐A‐D architectured 9‐(2‐ethylhexyl)‐9H‐carbazoles, connecting the mono/dimethoxyphenyl substituted cyanovinylene sidearms symmetrically at 3rd and 6th positions of the carbazole heterocycle (CZ1‐2), as potential hole‐transporting materials (HTMs). The current work highlights their structural, photophysical, thermal, electrochemical and theoretical investigations, including their structure‐property correlation studies. Evidently, the optical studies showcased their excellent fluorescence ability due to their push–pull natured structure with extended π‐conjugation. Further, in‐depth solvatochromic studies demonstrated their intramolecular charge‐transfer (ICT)‐dominated optoelectronic behavior, supported by various correlation studies. Also, the optical results revealed that CZ1 and CZ2 display λabs and λemi in the order of 410–430 nm and 530–560 nm, respectively, with a bandgap in the range of 2.5–2.6 eV. Finally, their quantum chemical simulations have provided an insight into the predictions of their structural, molecular, electronic and optical parameters. Conclusively, the study furnishes a deeper understanding of the intricacies involved in the structural modification of carbazole‐based HTMs for achieving better performance.

Vibration assisted machining is an advanced non-conventional precision machining technique aiming at improving the machining performance by superimposing a small amplitude, high-frequency vibration either on the tool or on the workpiece. This article presents the mechanical design, electromechanical simulation, and experimentation on the developed prototype of the flexural hinged micro XY stage for the vibration-assisted micro-milling system. The micro XY stage comprises three layers of flexural hinge structure surrounding the central parallel kinematic structure. The finite element analysis method is adopted to evaluate the static structural stiffness and harmonic behaviour. Two multilayer piezoelectric stack actuators drive the micro XY stage in X and Y directions. The experimental results show that the micro XY stage has a vibrating work area of 17.06 µm × 17.11 µm with a hysteresis nonlinearity and cross-coupling displacements on both axes. Therefore, an electromechanical model is essential to compensate for the hysteresis behaviour and cross-coupling displacements. Open-loop tracking control experiments determine the accuracy of the developed electromechanical model. Implementing a combined hysteresis and cross-coupling displacement compensation approach into the electromechanical model resulted in an open-loop tracking error of 7% for the synchronised circular path and a maximum deviation of 0.6 µm from the linear path.

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SummaryThis work presents the design of an asynchronous digital finite impulse response (FIR) filter suitable for high‐performance partial response maximum likelihood (PRML) read channel ICs. A high throughput, low latency FIR filter is the basic requirement for the equalization process in read channels. To achieve the enhancement in speed and reduction in latency of the FIR filter, its computational units are deeply pipelined using high‐capacity hybrid (HC‐hybrid) logic pipeline method. The designed FIR filter has been simulated using UMC‐180 nm and UMC‐65 nm technologies. Simulation results show that the asynchronous digital FIR filter can operate up to a throughput of 1.17 Giga items/s in 180 nm and 2.3 Giga items/s in 65 nm technology yet with the latency in the order of ns.