Large-scale wurtzite GaN nanowires and nanotubes were grown by direct reaction of metal gallium vapor with flowing ammonia in an 850–900 °C horizontal oven. The cylindrical structures were as long as 500 μm with diameters between 26 and ∼100 nm. Transmission electron microscopy, scanning electron microscopy, and x-ray diffraction were used to measure the size and structures of the samples. Preliminary results show that the size of the nanowires depends on the temperature and the NH3 flow rate. The growth mechanism is discussed briefly. The simple method presented here demonstrates that GaN nanowires can be grown without the use of a template or catalyst, as reported elsewhere.

Collagen, which is the most abundant protein in mammals, is demonstrated as a substrate for flexible implantable electronics. Using electron beam deposition, devices are fabricated on transparent collagen type I films. Several applications, including a strain gauge, a wireless antenna, a heater, and a temperature sensor, are demonstrated, showcasing the promising future applications of this substrate for implantable biomedical devices for monitoring of physiological environment.

Si-rich Si 3 N 4 (SRN) thin films were investigated to understand the various defect states present within the SRN that can lead to reduced performance in quantum dot based devices made of these materials. The SRN films, deposited by low pressure chemical vapor deposition followed by furnace anneals over a range of temperatures, were determined to be comprised of two distinct phase separated SRN regions with different compositions (precipitates within a host matrix). Photoluminescence (PL) spectra showed multiple peaks convoluted together within the visible and near-visible range. Depending on deposition and annealing conditions, the films displayed changes in PL peak intensities which were correlated with chemical bonding utilizing x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, spectroscopic ellipsometry, and capacitance-voltage measurements. It is found that the PL originates from defect-state to defect-state and band edge to defect-state electronic transitions. V

The change in residual stress in PECVD amorphous silicon carbide (a-SiC:H) films exposed to air and wet ambient environments is investigated. A close relationship between stress change and deposition condition is identified from mechanical and chemical characterization of a-SiC:H films. Evidence of amorphous silicon carbide films reacting with oxygen and water vapor in the ambient environment are presented. The effect of deposition parameters on oxidation and stress variation in a-SiC:H film is studied. It is found that the films deposited at low temperature or power are susceptible to oxidation and undergo a notable increase in compressive stress over time. Furthermore, the films deposited at sufficiently high temperature (≥ 325 °C) and power density (≥ 0.2 Wcm −2 ) do not exhibit pronounced oxidation or temporal stress variation. These results serve as the basis for developing amorphous silicon carbide based dielectric encapsulation for implantable medical devices.

Collagen is an important component of the extracellular matrix. In article number 1500154, Slobodan Dimitrijevich, Majid Minary‐Jolandan, and co‐workers demonstrate its use as a substrate for implantable flexible electronics. Scanning electron microscopy (SEM) imaging shows collagen molecules forming a transparent film onto which gold metal is deposited using electron‐beam deposition to make flexible conductive metal patterns for resistors, strain/temperature sensors, and antennas that can wirelessly power light‐emitting diodes (LEDs).