Tuning of noble metal work function with organophosphonate nanolayers

Ramanath, Ganpati; Kwan, Matthew; Chow, Philippe K.; Quintero, Yenny Cardona; Mutin, P. Hubert; Ramprasad, Rampi

doi:10.1063/1.4890486

Cited by 11 publications

(8 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recently, we showed that interfacial electrical transport across metallized V–VI thermoelectric materials is strongly dependent on interdiffusion and phase formation, and the majority carriers. Prior works have shown that introducing a nanomolecular layer (NML) at metal–insulator interfaces can inhibit diffusion, , influence phase formation pathways, enhance interfacial toughness and thermal conductance, , and alter the effective work function of the metal . A recent study reported improvements in electrical contact conductivity Σ c upon introducing an organosilane NML at Ni-metallized Bi 2 Te 3– x Se x interfaces .…”

mentioning

confidence: 99%

“…Prior works have shown that introducing a nanomolecular layer (NML) at metal−insulator interfaces can inhibit diffusion, 8,9 influence phase formation pathways, 10 enhance interfacial toughness 11 and thermal conductance, 12,13 and alter the effective work function of the metal. 14 A recent study reported improvements in electrical contact conductivity Σ c upon introducing an organosilane NML at Ni-metallized Bi 2 Te 3−x Se x interfaces. 15 However, the property enhancement mechanism is not yet studied and understood in terms of interface chemistry and phase formation.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Tailoring Electrical Transport Across Metal–Thermoelectric Interfaces Using a Nanomolecular Monolayer

Cardinal

Devender

Borca‐Tasciuc

et al. 2016

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

We report a 13-fold increase in electrical contact conductivity Σc upon introducing a 1,8-octanedithiol (ODT) monolayer at Cu-Bi2Te3 interfaces. In contrast introducing ODT at Ni-Bi2Te3 interfaces results in a 20% decrease in Σc. Rutherford backscattering spectrometry, X-ray diffraction and electron spectroscopy analyses indicate that metal-sulfur and sulfur-Bi2Te3 bonds at metal-Bi2Te3 interfaces inhibit chemical mixing, curtail metal-telluride formation, and suppress oxidation. Suppressing p-type Cu2Te favors electrical transport across Cu-metallized n-type Bi2Te3, whereas inhibiting the formation of Ohmic-contact-promoting NixTey compromises the electrical conductance at Ni-Bi2Te3 interfaces. Our findings illustrate that molecular nanolayers could be attractive for manipulating interface chemistry and phase formation for tailoring electrical transport across metal-thermoelectric interfaces for solid-state refrigeration applications.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Tailoring Electrical Transport Across Metal–Thermoelectric Interfaces Using a Nanomolecular Monolayer

Cardinal

Devender

Borca‐Tasciuc

et al. 2016

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

show abstract

“…PA SAMs on indium tin oxide (ITO) are of particular interest due to the extensive use of this material in the electronics and photovoltaics industry. PA SAMs have been reported to act as a resist for wet etching [17], to protect surfaces against corrosion [2,18], to modify the work function of transparent conductive oxides [19][20][21][22], and as a patterning layer for the metallization of heterojunction solar cells [23]. Recently, PA SAMs have also been shown to improve the perovskite solar cell efficiency when used as or within charge-transporting layers [24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

“…The favored deposition method for perovskite solar cells applications are reported to be either immersion or spin-coating of low concentration PA solutions in methanol or ethanol but the surface coverage by the phosphonic acids remained uncharacterized [24][25][26]. Tuning the work function of the conductive oxide layer is likely to be very sensitive to the coverage as well as the presence of multilayers or pinholes [19,20,29]. Spray-coating methods have been reported to provide self-assembled monolayers of the small molecule pentafluorobenzyl phosphonic acid with good coverage on ITO and indium zinc oxide (IZO) when compared to a 1 h immersion at 75 °C [28].…”

Section: Introductionmentioning

confidence: 99%

Spray coating vs. immersion for self-assembly of gemini perfluorinated phosphonic acids on indium tin oxide

et al. 2021

View full text Add to dashboard Cite

Self-assembled monolayers (SAMs) are widely used to engineer the surface properties of metals and metal oxide layers. This article reports the fabrication of gemini perfluorinated phosphonic acids SAMs on indium tin oxide (ITO). The self-assembled monolayers are to be used for patterning nickel lines by electroplating on ITO in order to obtain low-cost conductor grids on heterojunction solar cells. The aim is to develop large-scale, low-cost processes that will both reduce production times and produce strong, covalently bonded monolayers of phosphonic acids on metal oxide surfaces along with uniform coverage. The gemini perfluorinated phosphonic acid provides extremely high hydrophobicity at the surface of ITO with a static contact angle of water above 115 ° and a remarkably low hysteresis of approximately 15 ° between advancing and receding contact angles. Well-known octadecylphosphonic acid is used as a reference material. Two deposition methods, by immersion and by spray-coating, are compared for the self-assembly of the molecules. The effect of the solvents used during the immersion, spraycoating, and rinsing steps are investigated. The surface properties are characterized by atomic force microscopy, contact angle measurements, and attenuated total reflectance Fouriertransform infrared spectroscopy.

show abstract

“…Sensitivity of photoresponse to the relative position of the sample. References(27)(28)(29)(30)(31)(32)(33)(34)(35)…”

mentioning

confidence: 99%

Optical manipulation of work function contrasts on metal thin films

Ravi

Sun²,

Nandakumar

et al. 2018

Sci. Adv.

View full text Add to dashboard Cite

Work function is a crucial metric in every optoelectronic device to ensure a specific charge transport scheme. However, the number of stable conductive materials available in a given work function range is scant, necessitating work function modulation. As opposed to all the previous chemical methods of work function modulation, we introduce here an alternative approach involving optical modulation. The work function is the minimum energy needed to eject an electron from a solid into vacuum and is known to be light-intensity-independent. A "light intensity dependent" change in work function was observed in metallic thin films coated on a semiconductor. This new phenomenon, contrasting the existing notions on work function, was tested and affirmed with three different systems, namely, Au/n-Si, Pt/n-Si, and W/n-Si. A work function shift of 0.22 eV is achieved in the Pt/n-Si system merely by tuning the illumination intensity from 0 to 18 mW/cm 2 . Continuous tuning of work functions to a specified range is now possible just by tuning the light intensity with a few discrete metals in hand. Moreover, selective illumination creates a work function contrast on the metal film, enabling in-plane charge transport. This throws new light on the design and understanding of the optoelectronic devices. In light of this, we also present a simple photodetector design that is sensitive to illumination direction.

show abstract

Tuning of noble metal work function with organophosphonate nanolayers

Cited by 11 publications

References 43 publications

Tailoring Electrical Transport Across Metal–Thermoelectric Interfaces Using a Nanomolecular Monolayer

Tailoring Electrical Transport Across Metal–Thermoelectric Interfaces Using a Nanomolecular Monolayer

Spray coating vs. immersion for self-assembly of gemini perfluorinated phosphonic acids on indium tin oxide

Optical manipulation of work function contrasts on metal thin films

Contact Info

Product

Resources

About