Electro-optic modulators transform electronic signals into the optical domain and are critical components in modern telecommunication networks, RF photonics, and emerging applications in quantum photonics and beam steering. All these applications require integrated and voltage-efficient modulator solutions with compact formfactors that are seamlessly integratable with Silicon photonics platforms and feature near-CMOS material processing synergies. However, existing integrated modulators are challenged to meet these requirements. Conversely, emerging electro-optic materials heterogeneously integrated with Si photonics open a new avenue for device engineering. Indium tin oxide (ITO) is one such compelling material for heterogeneous integration in Si exhibiting formidable electro-optic effect characterized by unity order index at telecommunication frequencies. Here we overcome these limitations and demonstrate a monolithically integrated ITO electrooptic modulator based on a Mach Zehnder interferometer (MZI) featuring a high-performance half-wave voltage and active device length product, VpL = 0.52 V•mm. We show, how that the unity-strong index change enables a 30 micrometer-short pphase shifter operating ITO in the index-dominated region away from the epsilon-bear-zero ENZ point. This device experimentally confirms electrical phase shifting in ITO enabling its use in multifaceted applications including dense on-chip communication networks, nonlinearity for activation functions in photonic neural networks, and phased array applications for LiDAR.
The rapid chemistry and processing development along with exploring underlying fundamentals [1,2] have increased the performance of perovskite solar cells (PSCs) to over 25%, [3] making them a potential candidate for nextgeneration photovoltaics (PVs). PSCs consist of a photoabsorber film sandwiched between n-type and p-type charge transport films, [4] all shown to be solution processable and thus, fabricable using scalable depositions such as slot die, [5,6] gravure, [7] spray, [8] and inkjet-printing systems [9,10] through automated manufacturing. The deposition of thin films from solutions has been shown for the SnO 2 electron transport layer (ETL), perovskite, and carbon electrodes. After deposition, these layers should undergo drying and possibly an annealing step; thus, the production of PSCs is suitable for automated manufacturing.To realize automated fabrication of PSCs with required control of the printing and IPL annealing processes, we integrated these processes into the "NeXus," a custom-designed system with robotics and motion control capabilities. The NeXus is a novel instrument for flexible multiscale manufacturing, implementing precision robotic assembly, additive manufacturing, and multiscale integration of miniature devices and systems. In addition to a commercial IPL annealing subsystem from Xenon Corporation, USA, the NeXus includes a deposition subsystem, a Pico Pulse Inkjet printhead from Nordson Corporation, USA. Samples move between these subsystems with the help of a custom 6 degree-of-freedom (DOF) robotic positioner, allowing not only fast transport of the samples between the processing tools, but also precise motion control during printing. The NeXus also integrates other manufacturing techniques, such as a dual-head fused deposition modeling (FDM) 3D printing, aerosol jetting, and microassembly. [11][12][13] Furthermore, a novel bonding process has been developed utilizing an ultrasonic vibration technique to embed metal wire in a polymer. [14,15] Slot-die coating is the most studied method for versatile and low-cost scalable deposition of thin-film PSCs, [6,16,17] whereas inkjet printing allows for the deposition of extremely high-resolution features with desired patterns. Inkjet-printing systems utilize thermal or piezoelectric drop-on-demand (DOD) technologies, where the latter produces more uniform size droplets and enables better distribution as a result of rapid
While stress-free and tensile films are well-suited for released in-plane MEMS designs, compressive films are needed for released out-of-plane MEMS structures such as buckled beams and diaphragms. This study presents a characterization of stress on a variety of sputtered and plasma-enhanced chemical vapour deposition (PECVD)-deposited films, including titanium tungsten, invar, silicon nitride and amorphous silicon, appropriate for the field of bistable MEMS. Techniques and strategies are presented (including varying substrate bias, pressure, temperature, and frequency multiplexing) for tuning internal stress across the spectrum from highly compressive (−2300 MPa) to highly tensile (1500 MPa). Conditions for obtaining stress-free films are also presented in this work. Under certain conditions during the PECVD deposition of amorphous silicon, interesting ‘micro-bubbles’ formed within the deposited films. Strategies to mitigate their formation are presented, resulting in a dramatic improvement in surface roughness quality from 667 nm root mean square (RMS) to 16 nm RMS. All final deposited films successfully passed the traditional ‘tape test’ for adhesion.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.