Preparation of hydrogenated amorphous germanium nitrogen alloys by plasma enhanced chemical vapor deposition

No abstract

High quality polythiophene films have been grown using a vapor-deposition process using polythiophene powder as the starting material. The powder was placed in an open quartz crucible (housed in a tungsten basket) and heated by running a high current (10–20 A) through it. The evaporated material was deposited onto a glass substrate placed roughly 3 cm above the crucible. The as-deposited, undoped polythiophene film has been characterized using x-ray photoelectron spectroscopy and is contrasted with the initial polythiophene powder. The reported spectra include survey and high resolution scans for the major photoelectron peaks. It is noted that these results compare favorably with previously published spectra from polythiophene grown using the more conventional chemical or electrochemical methods.

Cadmium Sulfide/Cadmium Telluride (CdS/CdTe) devices are subject to stress under various biases. Striking differences are observed with the Current-Voltage, and Capacitance- Voltage measurements for cells degraded at 100°C in dark under forward (FB), open circuit (OC), and reverse (RB) biases. RB stress provides the greatest degradation, and the apparent doping density profile shows anomalous behavior at the zero bias depletion width. Thin films of CdS, both doped and undoped, with Cu are characterized with photoluminescence (PL). The PL spectra from the CdS films are correlated with the CdS spectra from stressed devices, revealing that Cu signatures in the CdS layer of stressed devices are a function of stress biasing. Device modeling using AMPS-1D produces IV curves similar to that in RB degraded devices, by only varying the trap level concentration in the CdS layer.

Chitosan, a polymer of N‐acetylglucosamine, has been shown to have activity against both gram‐positive and gram‐negative bacteria at low pH. However, chitosan is insoluble at physiological pH, reducing its utility as an antimicrobial agent. Poly (acetyl, arginyl) glucosamine (PAAG), a chitosan‐arginine conjugate soluble at physiological pH, has been synthesized and shown to have similar antibacterial activity. PAAG’s solubility at physiological pH may be attributed to the guanidinium moiety’s positive charge, but the effect of the guanidinium on the polymer’s bioactivity is unclear. In order to explore the effects of positive charge on chitosan conjugates’ solubility and activity, we have synthesized an ornithine‐chitosan conjugate and investigated its antimicrobial activity. We present a synthetic route toward the ornithine‐chitosan conjugate and data regarding the conjugate’s antimicrobial activity.