Polymer studies semiconductors

Since the discovery of doped polyacetylene, a range of polymer-intense semiconductor devices have been studied including normal transistors and field-effect transistors (FETs), and photodiodes and light-emitting diodes (LEDs). Like conductive polymers, these materials obtain their properties due to their electronic nature, specifically the presence of conjugated pi-bonding systems. 

Finally, Majda has investigated a novel inorganic membrane-modified electrode [32]. The membrane used was a microporous alumina prepared by anodizing metallic aluminum in an acidic electrolyte [33]. Majda et al. lined the pores of these membranes with polymers and self-assembled monolayers and studied electron and ion transfer down the modified pore walls to a substrate electrode surface [32]. Martin and his coworkers have used the pores in such membranes as templates to prepare nanoscopic metal, polymer, and semiconductor particles [34],... 

Many of the earliest studies focused on the use of polymer-coated semiconductor materials for the reduction of C02. An example was the study of Aurian-Blajeni et al., who electropolymerized polyaniline onto p-Si [116]. In an aqueous C02-saturated solution, a total faradaic efficiency for formic acid and formaldehyde of 28% was achieved, but at a potential of—1.9 V (versus SCE). Likewise, Cabrera and Abruna electropolymerized [Re(CO)3(v-bpy)Cl], where v-bpy is 4-vinyl-4 -methyl-2,2 -bipyridine [117]. For CO production, TONs of about 450 were observed, while the faradaic efficiencies approached 100%. Upon illumination in acetonitrile solution, the onset potential for reduction was -0.65 V (versus SCE). 

Not all these cited studies have focused on photodriven HER and OER applications for the coated semi-conductor/electrolyte interfaces. Ae.c.p.= electronically-conducting polymer, sc = semiconductor... 

In the next sections we discuss some selected examples of the use of ATR spectroscopy to study semiconductors, polymers, and corrosion processes. 

Table VI includes the electrical and magnetic properties of the polymers studied. Polyacetylene is a semiconductor. In contrast, the conductivities of the Si-containing polyacetylenes are only in the order of S/cm,...

In some special cases, the two approaches can be combined with the normal Raman or resonance Raman spectroscopy to comprehensively study a film electrode. For example, a thin film of polymer, oxide, semiconductor, or Langmuir- Blodgett (LB) film is coated in different ways onto the SERS-active substrate, such as Fig. 18(a). The SERS spectrum recorded at this stage can provide the bottom layer structure of the film. The film can then be deposited as a thicker layer, which enables the Raman signal from the bulk phase to be sufficiently strong and detected by normal Raman... 

Other chemical apphcations being studied include the use of microwaves in the petroleum (qv) industry (175), chemical synthesis (176,177), preparation of semiconductor materials (178), and the processing of polymers (179). 

N,N-bis(4-methylphenyl)-N,iV-bis(4-ethylphenyl)-[l,l -(3,3 -dimethyl)biphenyl]-4,4 -diamine [115310-63-9] (ETPD) (8) -doped PMPS (Table 1, entry 22), hole mobihty approaching 10 cm /Vs at 2.5 x 10 V/cm was observed (48). This is the highest recorded hole mobihty for disordered organic systems. From this perceptive, it is very interesting to study the carrier mobihty of polymers heavily doped with semiconductor nanoclusters. 

Three common uses of RBS analysis exist quantitative depth profiling, areal concentration measurements (atoms/cm ), and crystal quality and impurity lattice site analysis. Its primary application is quantitative depth profiling of semiconductor thin films and multilayered structures. It is also used to measure contaminants and to study crystal structures, also primarily in semiconductor materials. Other applications include depth profilii of polymers, high-T superconductors, optical coatings, and catalyst particles. ... 

In low-dimensional systems, such as quantum-confined. semiconductors and conjugated polymers, the first step of optical absorption is the creation of bound electron-hole pairs, known as excitons [34). Charge photogcncration (CPG) occurs when excitons break into positive and negative carriers. This process is of essential importance both for the understanding of the fundamental physics of these materials and for applications in photovoltaic devices and photodctcctors. Since exciton dissociation can be affected by an external electric field, field-induced spectroscopy is a powerful tool for studying CPG. 

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