Chemical synthesis of transparent and conducting polyaniline-poly(ethylene terephthalate) composite films

The thermal degradation behavior of indium tin oxide (ITO) thin films coated on glass substrates using radio frequency (rf) magnetron sputtering was investigated over the temperature range of 100–400 °C in air. The resistivity of ITO films increases abruptly after the thermal degradation temperature of 250 °C is reached, with a slight increase from 200 to 250 °C. The x-ray photoelectron spectrometry intensity ratio of O/(In + Sn) in thermally degraded ITO films is higher than that in normal films. The carrier concentration gradually decreases up to 200 °C, sharply drops between 200 and 250 °C with increasing temperature, and then saturates from 275 °C. The Hall mobility drops suddenly at 275 °C. The diffusion of oxygen into oxygen interstitials and oxygen vacancies and the chemisorption of oxygen into grain boundaries decrease the carrier concentration and the Hall mobility, respectively. The former mainly affects the resistivity of ITO films below 250 °C, and the later above 250 °C.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0884291400088117

Thermal degradation behavior of indium tin oxide thin films deposited by radio frequency magnetron sputtering

For low-dimensional materials, size effect of a physical property is usually expected to occur when one (or more) of the dimension sizes decreases to that comparable to or smaller than one of the intrinsic characteristic lengths, e.g., the mean free path. We report here an unexpected size effect, that in centimeter-long stripes of 100-nm-thick metallic thin films, a reduction of the absolute value of thermopower occurs when the stripe width is in the order of 30-50 μm, which is 100–1000 times larger than the intrinsic mean free path of the material. When the stripe width is reduced to 1.5 μm, a relative reduction of thermopower up to 35% is measured in some metals. We suggest that the sidewall scattering due to rough edges of these stripes may be the origin of this unexpected phenomenon. The results may be applied to construct novel thermoelectric devices, such as thermocouples made from a single metal film.

Unexpected size effect in the thermopower of thin-film stripes

We report the evolution of electrical transport and grain size during the sintering of thin films spin-cast from soluble phosphine and amine-bound, chloride-terminated cadmium selenide nanocrystals. Sintering of the nanocrystals occurs in three distinct stages as the annealing temperature is increased: (1) reversible desorption of the organic ligands (≤150 °C), (2) irreversible particle fusion (200–300 °C), and (3) ripening of the grains to >5 nm domains (>200 °C). Grain growth occurs at 200 °C in films with 8 atom % Cl–, while films with 3 atom % Cl– resist growth until 300 °C. Fused nanocrystalline thin films (grain size = 4.5–5.5 nm) on thermally grown silicon dioxide gate dielectrics produce field-effect transistors with electron mobilities as high as 25 cm2/(Vs) and on/off ratios of 105 with less than 0.5 V hysteresis in threshold voltage without the addition of indium.

https://pubs.acs.org/doi/pdf/10.1021/nn502829s

Electrical transport and grain growth in solution-cast, chloride-terminated cadmium selenide nanocrystal thin films.

Preparation and properties of transparent conducting indium tin oxide films deposited by reactive evaporation

Preparation and characterization of indium tin oxide films produced by the d.c. sputtering technique

Characterization of CdS film prepared by hot wall technique

Electric, galvanomagnetic and electrothermal properties of vacuum-evaporated antimony films

The thermoelectric power (TEP) of aluminum film was measured in the thickness range of 300–1600 A. From the size effect of electron diffusion term, the energy dependence of the mean free path of conduction electrons (U) and the Fermi surface area (V) were calculated to be U=0.957 and V=1.322. The phonon‐drag part of TEP also exhibited a size effect from which the mean free path of the dominant phonon mode was estimated to be 400 A. The effect of grain boundary scattering on thermoelectric power was also studied.

D. De

Papers

Preparation and characterization of indium tin oxide films produced by the d.c. sputtering technique

Characterization of CdS film prepared by hot wall technique

Electric, galvanomagnetic and electrothermal properties of vacuum-evaporated antimony films

Thermoelectric power of aluminum films

Thermoelectric power of vacuum-evaporated tin films