Comparison of the Stability of Functionalized GaN and GaP

Abstract

Surface functionalization via 1 H,1 H,2 H,2H-perfluoro octanephosphonic acid was done in the presence of phosphoric acid to provide a simplified surface passivation technique for gallium nitride (GaN) and gallium phosphide (GaP). In an effort to identify the leading causes of surface instabilities, hydrogen peroxide was utilized as an additional chemical modification to cap unsatisfied bonds. The stability of the surfaces was studied in an aqueous environment and subsequently characterized. A physical characterization was carried out to evaluate the surface roughness and water hydrophobicity pre and post stability testing via atomic force microscopy and water goniometry. Surface-chemistry changes and solution leaching were quantified by X-ray photoelectron spectroscopy and inductively coupled plasma mass spectrometry. The results indicate a sensitivity to hydroxyl terminated species for both GaN and GaP under aqueous environments, as the increase of the degree of leaching was more significant for hydrogen peroxide treated samples. The results support the notion that hydroxyl species act as precursors to gallium oxide formation and lead to subsequent instability in aqueous solutions.

Noninvasive Stimulation of Neurotypic Cells Using Persistent Photoconductivity of Gallium Nitride

“…After one day of incubation in a solution, the amount of gallium leached increases in the cell culture wells with GaN, but remains bellow 750 ppt. These results are in agreement with a number of ICP-MS analysis we have published on GaN with different polarities and compositions. − The ICP-MS data we collected for the present work confirms that leaching of gallium ions during the initial stimulation of the cells does not occur and will therefore not obscure the interpretation of results.…”

Growth of 2D MoP single crystals on liquid metals by chemical vapor deposition

“…The results are coincident with the fact that Ga spontaneously forms an oxide layer under ambient conditions [26]. The peak of Ga-P (1117.3 eV) is not detected [27], also indicating the high purity of the prepared MoP. Moreover, Raman spectrum of MoP single crystals was performed with one notable peak at 409 cm −1 (Fig.…”

Persistent Photoconductivity, Nanoscale Topography, and Chemical Functionalization Can Collectively Influence the Behavior of PC12 Cells on Wide Bandgap Semiconductor Surfaces

“…In addition, we treated the surface with 30% hydrogen peroxide solution. The peroxide treatment results in the formation of oxyhydroxide on the surface that is more stable in solution and gives hydroxide functionalization on the top layer . We have reported the detailed characterization of the in situ functionalization in prior work …”