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Abstract The ability to design and dynamically control chiroptical responses in solid-state matter at a wafer scale enables new opportunities in various areas. Here, we present a full stack of computer-aided designs and experimental implementations of a dynamically programmable, unified, scalable chiroptical heterostructure containing wafer-scale twisted aligned one-dimensional carbon nanotubes and non-volatile phase change materials. We develop a software infrastructure based on high-performance machine learning frameworks, including differentiable programming and derivative-free optimization, to efficiently optimize the tunability of both reciprocal and nonreciprocal circular dichroism responses, which are experimentally validated. Further, we demonstrate the heterostructure scalability regarding stacking layers and the dual roles of aligned carbon nanotubes - the layer to produce chiroptical responses and the Joule heating electrode to electrically program phase change materials. This heterostructure platform is versatile and expandable to a library of one-dimensional nanomaterials, phase change materials, and electro-optic materials for exploring novel chiral phenomena and photonic and optoelectronic devices. 

Proper derivation of CH3NH3PbX3 (CH3NH3+ = methyl ammonium or MA+; X- = Cl-, Br-, I-) optical constants is a critical step toward the development of high-performance electronic and optoelectronic perovskite devices. To date, the optical dispersion regimes at, above, and below the band gap of these materials have been inconsistently characterized by omitting or under-approximating anomalous spectral features (from ultraviolet to infrared wavelengths). In this report, we present the rigorous optical dispersion data analysis of single crystal MAPbBr3 involving variable angle spectroscopic ellipsometry data appended with transmission intensity data. This approach yields a more robust derivation of MAPbBr3 optical constants (refractive index, n, and extinction coefficient, k) for both anomalous (absorptance) and normal (no absorptance) optical dispersion regimes. Using the derived optical constants for our MAPbBr3 single crystals, illustrative modeled solar cell device designs are presented in relation to non-realistic designs prepared using representative optical constants reported in the literature to date. In comparison, our derived optical dispersion data enables the modeled design of realistic planar perovskite solar cell (PSC) optical performance where the active layer (MAPbBr3) is optimized for maximum solar radiation absorption. We further demonstrate optimized modeled planar PSC designs with minimal parasitic optical absorptance in non-active PSC device layers resulting in improved performance at broad angles of incidence (approximately 0-70°). Our robust derivation of MAPbBr3 optical properties is expected to impact the optical dispersion data analysis of all perovskite analogs and expedite targeted development of, for example, solar cell, light-emitting diode, photo and X-ray/γ-ray detector, and laser system technologies. 

Creating artificial matter with controllable chirality in a simple and scalable manner brings new opportunities to diverse areas. Here we show two such methods based on controlled vacuum filtration - twist stacking and mechanical rotation - for fabricating wafer-scale chiral architectures of ordered carbon nanotubes (CNTs) with tunable and large circular dichroism (CD). By controlling the stacking angle and handedness in the twist-stacking approach, we maximize the CD response and achieve a high deep-ultraviolet ellipticity of 40 ± 1 mdeg nm⁻¹. Our theoretical simulations using the transfer matrix method reproduce the experimentally observed CD spectra and further predict that an optimized film of twist-stacked CNTs can exhibit an ellipticity as high as 150 mdeg nm⁻¹, corresponding to agfactor of 0.22. Furthermore, the mechanical rotation method not only accelerates the fabrication of twisted structures but also produces both chiralities simultaneously in a single sample, in a single run, and in a controllable manner. The created wafer-scale objects represent an alternative type of synthetic chiral matter consisting of ordered quantum wires whose macroscopic properties are governed by nanoscopic electronic signatures and can be used to explore chiral phenomena and develop chiral photonic and optoelectronic devices.