Single-crystalline gallium phosphide (GaP) surfaces have been functionalized with alkyl groups via a sequential Cl-activation, Grignard reaction process X-ray photoelectron (XP) spectra of freshly etched GaP(111)A surfaces demonstrated reproducible signals for surficial Cl after treatment with PCl(5) in chlorobenzene The measured Cl content consistently corresponded to approximately a monolayer of coverage on GaP(111)A In contrast, GaP(111)B surfaces treated with the same PCl(5) solution under the same conditions exhibited macroscale roughening and yielded XP spectra that showed irreproducible Cl surface content often below the limit of detection of the spectrometer The Cl-activated GaP(111)A surfaces were reactive toward alkyl Grignard reagents Sessile contact angle measurements between water and GaP(111)A after various levels of treatment showed that GaP(111)A surfaces became significantly more hydrophobic following reaction with either CH(3)MgCl or C(18)H(37)MgCl GaP(111)A surfaces reacted with C(18)H(37)MgCl demonstrated wetting properties consistent with surfaces modified with a dense layer of long alkyl chains High-resolution C 1s XP spectra indicated that the carbonaceous species at GaP(111)A surfaces treated with Grignard reagents could not be ascribed solely to adventitious carbon A shoulder in the C 1s XP spectra occurred at slightly lower binding energies for these samples, commensurate with the formation of Ga-C bonds High-resolution P 2p XP spectra taken at various times during prolonged direct exposure to ambient laboratory air indicated that the resistance of GaP(111)A to surface oxidation was greatly enhanced after surface modification with alkyl groups GaP(111)A samples that had been functionalized with C(18)H(37)- groups exhibited less than 01 nm of surface oxide after 7 weeks of continuous exposure to ambient air GaP(111)A surfaces terminated with C(18)H(37)- groups were also used as platforms in Schottky heterojunctions with Hg In comparison to freshly etched GaP(111)A, the alkyl-terminated GaP(111)A samples yielded current-voltage responses that were in accord with metal-insulator-semiconductor devices and indicated that this reaction strategy could be used to alter rates of heterogeneous charge transfer controllably The wet chemical surface functionalization strategy described herein does not involve thiol/sulfide chemistry or gas-phase pretreatments and represents a new synthetic methodology for controlling the interfacial properties of GaP and related Ga-based III-V semiconductors

Wet chemical functionalization of III-V semiconductor surfaces: alkylation of gallium phosphide using a Grignard reaction sequence.

108 – Phthalocyanine Thin Films: Deposition and Structural Studies

Synchrotron radiation photoelectron spectroscopy has been used to investigate III–V phosphide GaP and InP (100) surfaces treated with a neutralized (NH4)2S solution. Compared to the conventional basic (NH4)2S solution treatment, a thick sulfide layer with P–S bond and strong Ga–S (In–S) bond of high thermal stability is formed on the neutralized (NH4)2S-treated GaP (InP) (100) surfaces. The possible passivation mechanisms of the two (NH4)2S solutions to III–V phosphide surfaces are also discussed.

Neutralized (NH4)2S solution passivation of III–V phosphide surfaces

Investigation of the growth mechanism of layered semiconductor GaSe

The observable chemical, electrochemical, and morphological features of GaP(111) surfaces after wet chemical etching have been assessed using X-ray photoelectron spectroscopy, atomic force microscopy, and electrochemical impedance spectroscopy. HF(aq), NH4F(aq), H2SO4(aq), HCl(aq), HCl-HNO3(aq), and dilute Br-2 in CH3OH (with and without a follow-up alkaline etch) are all potent etchants for GaP(111) but yield distinctly different GaP(111)A and GaP(111)B surface conditions. Freshly etched GaP(111)B interfaces show higher residual oxide coverages and are generally rougher than similarly treated GaP(111)A surfaces. Differential capacitance measurements of n-GaP(111)A and n-GaP(111)B electrodes show that various etchants result in a wide range of apparent values for the conduction bandedge potentials, spanning approximately 700 mV in acetonitrile. These data show that these etched surfaces are not equivalent and that the observable physicochemical and electrochemical properties of GaP(111) are strongly influenced by the choice of wet chemical etchant. Additionally, X-ray photoelectron spectra show that adsorption of (4-fluorophenyl)methanethiol onto GaP(111) is insensitive to surface orientation or etching method, indicating no dominant covalent interaction between organic thiols and GaP(111) interfaces.

Physicochemical and Electrochemical Properties of Etched GaP(111)A and GaP(111)B Surfaces

Studies of the sulfur passivation of GaP(111) surfaces with solution treatments, and the subsequent molecular‐beam epitaxy growth and characterization of ultrathin films of layered semiconductors on those surfaces are presented in this article. Simple solution passivation procedures allow formation of a S–GaP(111) semiconductor surface which will support the growth of highly ordered layers of GaSe (Eband gap=2.05 eV). These thin GaSe layers then permit the further growth of ordered layers of a semiconductor like MoSe2 (Eband gap=1.0 eV) or an organic dye such as a phthalocyanine. Reflection high energy electron diffraction and angle‐resolved x‐ray photoelectron spectroscopy have been used to determine the structure and composition of the surface layers formed at each stage of the deposition process. Absorption spectra are used to characterize the band edge and A1,2 exciton energies of the MoSe2/GaSe S–GaP(111) thin films, and the position and shape of the phthalocyanine Q band.

Growth of layered semiconductors by molecular‐beam epitaxy: Formation and characterization of GaSe, MoSe2, and phthalocyanine ultrathin films on sulfur‐passivated GaP(111)

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

M. Lawrence

Author Tools

Chat about Author

Papers

Growth of layered semiconductors by molecular‐beam epitaxy: Formation and characterization of GaSe, MoSe2, and phthalocyanine ultrathin films on sulfur‐passivated GaP(111)