Low-Power and Ultra-Thin MoS Photodetectors on Glass.

Integration of low-power consumer electronics on glass can revolutionize the automotive and transport sectors, packaging industry, smart building and interior design, healthcare, life science engineering, display technologies, and many other applications. However, direct growth of high-performance, scalable, and reliable electronic materials on glass is difficult owing to low thermal budget. Similarly, development of energy-efficient electronic and optoelectronic devices on glass requires manufacturing innovations.

Mobility Deception in Nanoscale Transistors: An Untold Contact Story.

Mobility is a critical parameter that is routinely used for benchmarking the performance of field-effect transistors (FETs) based on novel nanomaterials. In fact, mobility values are often used to champion nanomaterials since high-performance devices necessitate high mobility values. The current belief is that the contacts can only limit the FET performance and hence the extracted mobility is an underestimation of the true channel mobility.

Engineered optical and electrical performance of rf-sputtered undoped nickel oxide thin films for inverted perovskite solar cells.

Inverted perovskite solar cells incorporating RF sputtered NiO thin films as a hole transport layer and window layer are demonstrated. The electrical and optical properties of the NiO thin films are engineered using varied sputtering conditions. The localized states within bandgap owing to its crystal disorder and nonstoichiometric features affect the transmittance and the optical bandgap of the NiO thin films which in turn influences the J of the perovskite solar cells.

Scanning electron microscopy of nanoscale chemical patterns.

A series of nanoscale chemical patterning methods based on soft and hybrid nanolithographies have been characterized using scanning electron microscopy with corroborating evidence from scanning tunneling microscopy and lateral force microscopy. We demonstrate and discuss the unique advantages of the scanning electron microscope as an analytical tool to image chemical patterns of molecules highly diluted within a host self-assembled monolayer and to distinguish regions of differential mass coverage in patterned self-assembled monolayers. We show that the relative contrast of self-assembled monolayer patterns in scanning electron micrographs depends on the operating primary electron beam voltage, monolayer composition, and monolayer order, suggesting that secondary electron emission and scattering can be used to elucidate chemical patterns.

A method for the fabrication of sculptured thin films of periodic arrays of standing nanorods.

A simple method for the fabrication of sculptured thin films (STFs) of periodic arrays of high-aspect-ratio (20:1) standing nanorods on silicon substrates is described. It is based on oblique evaporation onto periodically arranged arrays of "mini-rod" topography using a rotating sample stage. Recently, it has been shown that these nanostructures can be prepared on relatively large areas and at low cost, making the method suitable for technological applications.

Biological reduction of nanoengineered iron(III) oxide sculptured thin films.

Sculptured thin films (STFs) are assemblies of nominally identical, parallel nanowires with tailored shapes such as chevrons and spirals. A series of iron(lll) STFs were produced with varied crystallinity (from hematite toferrihydrite) and nanowire shapes (slanted columnar, clockwise helical, and counterclockwise helical). When the dissimilatory metal-reducing bacterium Shewanella putrefaciens CN32 was used to measure their bioreducibility, it was found that bioreduction was controlled primarily by oxide crystallinity.

Blue-shifting of circular Bragg phenomenon by annealing of chiral sculptured thin films.

The wavelength regime of the circular Bragg phenomenon, exhibited by chiral sculptured thin films fabricated using the serial bideposition technique, blue shifts as a result of post-deposition annealing. This blue shift can be attributed to the net effect of three material changes that occur during annealing: a small reduction in helical pitch, an increase in the relative permittivity of the column material changing from amorphous to crystalline, and a density reduction due to columnar thinning from the same amorphous-to-crystalline transition.