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Metal-organic framework (MOF) thin films offer exceptional properties for diverse applications, yet the mechanisms underlying MOF crystallization are not fully understood. Knowledge gaps remain regarding the nucleation and growth mechanisms of these highly porous, crystalline materials under dynamic evaporative conditions. Here, an in situ grazing incidence wide-angle X-ray scattering (GIWAXS) combined with a microkinetic model is used to probe the dynamic growth of MOF films. We show that while most high-order oligomers are produced in the solution phase, the key parameters that control thin-film growth are autocatalytic synthesis of secondary building units (SBUs) followed by physisorption on silicon wafer substrate, exponential growth due to evaporation-driven step growth, and transition to the stationary phase due to mass-transfer-limited growth. Importantly, this study demonstrates the applicability of this microkinetic modeling framework to predict film properties across a range of temperatures and reactant concentrations, allowing for rational design of MOF thin films. 

This work resolves the inter- and intramolecular polarized absorption of polarons in the organic semiconductor P3HT, allowing previous theoretical predictions to be tested. Vibronic coupling is shown to be crucial in understanding polaron absorption. 

II–IV–V 2 materials, ternary analogs to III–V materials, are emerging for their potential applications in devices such as LEDs and solar cells. Controlling cation ordering in II–IV–V 2 materials offers the potential to tune properties at nearly fixed compositions and lattice parameters. While tuning properties at a fixed lattice constant through ordering has the potential to be a powerful tool used in device fabrication, cation ordering also creates challenges with characterization and quantification of ordering. In this work, we investigate two different methods to quantify cation ordering in ZnGeP 2 thin films: a stretching parameter calculated from lattice constants , and an order parameter determined from the cation site occupancies ( S ). We use high resolution X-ray diffraction (HRXRD) to determine and resonant energy X-ray diffraction (REXD) to extract S . REXD is critical to distinguish between elements with similar Z -number ( e.g. Zn and Ge). We found that samples with a corresponding to the ordered chalcopyrite structure had only partially ordered S values. The optical absorption onset for these films occurred at lower energy than expected for fully ordered ZnGeP 2 , indicating that S is a more accurate descriptor of cation order than the stretching parameter. Since disorder is complex and can occur on many length scales, metrics for quantifying disorder should be chosen that most accurately reflect the physical properties of interest.