Effect Of Tin Doping Research Articles

Effects of Tin Doping and Oxygen Vacancies on the Electronic States of Indium Oxide

The electronic states of indium oxide are calculated by a molecular orbital method. The conduction band consists mainly of oxygen 2p and indium 5p. The valence band consists of O-2p. When there is an oxygen vacancy in the indium oxide, a localized orbital appears at the indium site near the oxygen vacancy, which forms a vacancy level below the bottom of the conduction band. When there are many oxygen vacancies in the indium oxide, the vacancy level is unlocalized. When Sn atoms are substituted for In atoms, localized molecular orbitals of Sn-5p and O-2p appear at the high-energy part of the conduction band. On the other hand, when Sn atoms are inserted into interstitial positions, vacancy levels appear below the bottom of the conduction band. When there are many oxygen vacancies in both cases, the oxygen vacancy levels appear between the conduction band and the valence band. The complex formed by In, Sn and O forms the doping level.

Deep-level photoluminescence studies of undoped and tin-doped (LEC) InP

The effects of tin doping on the deep-level photoluminescence (PL) spectra of (LEC) InP were studied. Specifically, the effect of rapid thermal annealing (RTA) on the deep emission bands labelled as band A (1.13 eV), band B (1.06 eV), band C (1.20 eV) and band D (0.97 eV) were investigated. Band A appeared in both undoped and doped samples, but it disappeared after RTA for all the samples. It is suggested that band A is due to the formation of a complex involving VIn with residual impurities. The disappearance of band A after RTA is concomitant with the appearance of bands B, C and D. The existence of band B is attributed to the complex formation of VP with residual impurities. Band C was observed after the annealing process both in undoped and lightly-tin-doped samples and is believed to be due to the formation of VP single point defects. Band D was only observed in heavily doped samples and it is believed to be the effect of InP antisite defects.

Spray-pyrolytic-grown ITO/InP junctions: effect of tin doping

The effect of tin concentration on the photovoltaic properties of indium tin oxide (ITO)/p-InP junctions prepared at 340 degrees C by the spray pyrolysis technique has been reported. With increasing tin concentration (up to 25% by weight) in the ITO films, the illuminated output parameters of the junctions, Voc. Jsc and fill factor (FF) (and consequently the efficiency) are affected very little, but appreciable changes are observed in the diode ideality factor (n), reverse saturation current (J0) and spectral response. A maximum efficiency of 10.7% has been achieved under 100 mW cm-2 illumination for junctions (without antireflection coating and top grid contact) having 5% by weight of tin. An attempt has been made to understand the results qualitatively.

Indium-tin oxide thin films prepared by chemical vapor deposition

Transparent conductive indium-tin oxide thin films were prepared by an atmospheric-pressure chemical vapor deposition method. The source materials were indium acetylacetonate and tin (II) acetylacetonate which are nontoxic and easy to handle. The polycrystalline films were obtained at a reaction temperature in the range of 350–500 °C. For the 215-nm-thick film deposited at 450 °C, the resistivity was 1.8 × 10−4 Ω cm, and the transmittance was more than 90% in the wave number range of above 400 nm. The atomic ratio Sn/In of the film was 0.031. The effects of tin doping on the structure and characteristics of the film were discussed on the basis of the carrier concentration and mobility which were measured by using the Hall effect.

Indium tin oxide thin films prepared by chemical vapour deposition

Transparent conductive indium tin oxide thin films were prepared by an atmospheric pressure chemical vapour deposition method without using an oxygen donor. The raw materials were indium 2-ethylhexanoate and tin(IV) chloride, which are inexpensive and easy to handle. Polycrystalline films were obtained at a reaction temperature of 400°C. The tin content in the film is adjustable by changing the ratio of the flow rate of the carrier gas. For a 430 nm thick film deposited at 400°C, the resistivity was 2.9×10 −4 Ω cm , and the transmittance was more than 80% in the wavenumber range above 550 nm. The effects of tin doping on the structure and characteristics of the film are discussed by comparing the results with the corresponding values for non-doped indium oxide film.

Effect of tin-doping on polytypism of melt-grown crystals of cadmium iodide

Abstract The effect of doping of metallic tin in cadmium iodide crystals has been systematically studied. The method of zone melting has been employed both for purification and for the growth of single crystals of cadmium iodide. The doping has been carried out by zone levelling technique. The as-grown crystals have been characterized by X-ray diffraction and physical methods. All the crystals have been found to consist of the most common polytype 4H. Unlike the case of pure undoped crystals of cadmium iodide grown from melt, all the X-ray photographs showed the presence of arcing. None of the photographs showed the presence of streaking. Besides, the doped crystal were found to be harder than the crystals of undoped cadmium iodide. Unlike the undoped crystals, cleavage in the doped crystals was found to be difficult and highly localized. The results have been discussed.

Effect of tin doping on InSb thin films

The behaviour of tin in InSb thin films is investigated. Tin is introduced to flash-evaporated InSb films by coevaporation of tin and InSb from separate evaporation sources. Subsequently the films are regrown by hot-wire zone melting. The morphology and chemical composition of the doped films are studied by means of scanning electron microscopy and by electron microprobe and conventional X-ray analysis. The effect of doping is also studied by Hall effect measurements. It is found that to the solubility limit of tin in InSb correspond tin and electron concentrations of (1.5±0.5) × 10 20 cm -3 and (3±1) × 10 18 cm -3 respectively. Below the solubility limit the electron concentration is only a small fraction (several per cent) of the tin concentration. In spite of the large tin content the electron mobilities in the regrown films are very high; they correspond roughly to the theoretical values calculated for uncompensated n-InSb. This high mobility is explained by the assumption that most of the tin atoms incorporate in the InSb in the form of electrically inactive Sn-Sn pairs by the substitution for the isoelectronic In-Sb pairs. It appears that tin is a very useful donor dopant for obtaining high electron mobility InSb films with electron concentrations up to 2 × 10 18 cm -3. In comparison with the group VI elements tin as a dopant to InSb thin films has several advantages, discussed in the text.