Donor-acceptor interfacial microstructures and fast ambipolar charge transport are pivotal in determining the device performance of inorganic-organic hybrid photovoltaics. Here, we report on a series of one-dimensional coaxial p-n... more
Donor-acceptor interfacial microstructures and fast ambipolar charge transport are pivotal in determining the device performance of inorganic-organic hybrid photovoltaics. Here, we report on a series of one-dimensional coaxial p-n junction core-shell nanohybrids formed by direct side-on attachment of carboxylated poly(3-alkylthiophene)s onto single-crystalline ZnO nanowires. The diameter of pristine ZnO nanowires is ∼30 nm, and the conjugated polymer forms a 2-10 nm shell around each nanowire. Spectroscopic studies on the resulting core-shell hybrid nanowires show an elongated conjugation length of the poly(3-alkylthiophene) backbone and fast electron transfer via ordered donor-acceptor interfaces. Hybrid nanowires in suspensions spontaneously undergo phase transitions from isotropic to nematic liquid crystalline phases via a biphasic region with increasing concentration. The unique liquid crystalline elasticity of nanohybrids results in large-area monodomain structures of aligned h...
A comparative study on interfacial crystallization of isotactic polypropylene (iPP) surrounding macroscopic carbon nanotube and graphene fibers has been carried out in single fiber polymer composites by means of in situ polarized optical... more
A comparative study on interfacial crystallization of isotactic polypropylene (iPP) surrounding macroscopic carbon nanotube and graphene fibers has been carried out in single fiber polymer composites by means of in situ polarized optical microscope, scanning electron microscope and X-ray diffraction. Ordered interfacial microstructures of iPP nucleate on both nanocarbon fibers in the form of a transcrystalline interphase. Nanotube fibers tend to promote negative birefringence transcrystals whereas graphene fibers induce positive birefringence transcrystals. The microstructures of transcrystals are strongly dependent on the thermal history and the double-layered transcrystals consisting of a negative inner layer and a positive outer layer occur under certain conditions. Transcrystallization kinetics has been studied and the Lauritzen–Hoffman theory of heterogeneous nucleation used to analyze the dynamic crystallization process. While the fold surface energy of iPP transcrystals surro...
Donor-acceptor interfacial microstructures and fast ambipolar charge transport are pivotal in determining the device performance of inorganic-organic hybrid photovoltaics. Here, we report on a series of one-dimensional coaxial p-n... more
Donor-acceptor interfacial microstructures and fast ambipolar charge transport are pivotal in determining the device performance of inorganic-organic hybrid photovoltaics. Here, we report on a series of one-dimensional coaxial p-n junction core-shell nanohybrids formed by direct side-on attachment of carboxylated poly(3-alkylthiophene)s onto single-crystalline ZnO nanowires. The diameter of pristine ZnO nanowires is ∼30 nm, and the conjugated polymer forms a 2-10 nm shell around each nanowire. Spectroscopic studies on the resulting core-shell hybrid nanowires show an elongated conjugation length of the poly(3-alkylthiophene) backbone and fast electron transfer via ordered donor-acceptor interfaces. Hybrid nanowires in suspensions spontaneously undergo phase transitions from isotropic to nematic liquid crystalline phases via a biphasic region with increasing concentration. The unique liquid crystalline elasticity of nanohybrids results in large-area monodomain structures of aligned h...
There is a national need to recruit more science teachers. Enhancing pathways to teaching for science, technology, engineering, and mathematics (STEM) majors could help to address this need. The Learn By Doing Lab is a course in which... more
There is a national need to recruit more science teachers. Enhancing pathways to teaching for science, technology, engineering, and mathematics (STEM) majors could help to address this need. The Learn By Doing Lab is a course in which STEM undergraduates teach hands-on life science and physical science to local third- through eighth-grade schoolchildren visiting the campus. To measure the impacts of this teaching experience on the undergraduate participants, we administered a version of the Science Teaching Efficacy Belief Instrument-Preservice survey at the start and end of the course. Significant gains were observed in the students' belief in their personal ability to effectively teach science (self-efficacy). Furthermore, qualitative and quantitative analysis of student reflections revealed that they perceived the Learn By Doing Lab experience to have helped them develop 21st-century competencies, particularly in the areas of collaboration, communication, and adaptability. Fi...
