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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 4 (1984), S. 68-78 
    ISSN: 0392-6737
    Keywords: Optical properties of thin films
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto Mediante la misura dei valori di transmittanza e di riflettanza per lunghezze d'onda comprese fra 0.25 μm e 3 μm, sono state studiate le proprietà ottiche di film sottili (trasparenti e conduttivi) di SnO2 non drogato, preparati mediante sputtering. Dai valori così ottenuti sono stati ricavati valori del gap diretto dell'ordine di 4 eV e di quello indiretto dell'ordine di 3 eV. Un film di SnO2 presenta tipicamente valori della transmittanza intorno all'85%, per luce visibile,R ∂ intorno ai (100÷800) Ω∂ e resistività fra 2.4·10−3 e 1.8·10−2 Ω cm.
    Abstract: Резюме Пзмеряя величины пропускания и отражения в области длин волн между λ=0.25 мкм и λ=3 мкм, исследуются оптические свойства проводящих прозрачных тонких пленок нелегированного SnO2, приготовленных с помощью напыления. Из полученных оптических постоянных извлекаются значения прямой щели, порядка 4 эВ, и непрямой щели, порядка 3 эВ. Типичные пленки SnO2 пропускают ∼85% видимого света, имеют сопротивлениеR ∂ (100÷800) Ω∂ и удельные сопротивления в области (2.4·10−3÷1.8·10−2) Ом·см.
    Notes: Summary The optical properties of conductive transparent thin films of undoped SnO2, prepared by using magnetron supttering, were studied by measuring the transmittance and the reflectance between λ=0.25 μm and λ=3μm. The extracted optical constants are interpreted to give values of a direct band gap of the order of 4 eV and of an indirect band gap of the order of 3 eV. Typical SnO2 films transmit ≈85% of visible light, have sheet resistanceR ∂ (100÷800) Ω∂ and resistivities of (2.4·10−3÷1.8·10−2) Ω cm.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 8 (1986), S. 447-463 
    ISSN: 0392-6737
    Keywords: Photoconduction and photovoltaic effects ; photodielectric effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto In questo lavoro si presenta un modello per la determinazione e l'ottimizzazione dei parametri fondamentali atti a definire la qualità delle celle solari amorfe, specificando le proprietà ottiche, elettriche e di ricombinazione. Esso può essere applicato a qualunque sistema di celle solari amorfe. Sono fornite le espressioni teoriche ed è descritto un metodo iterativo per il calcolo numerico della densità di corrente di alcuni tipi di celle. Sono anche presentati i risultati ottenuti da calcoli eseguiti col computer e basati su questo modello.
    Notes: Summary A model for determination and optimization of the fundamental parameters defining the quality of amorphous solar cells in which optical, electrical and recombination properties are specified is developed. It can be applied to any amorphous solar-cell systems. This paper gives theoretical expressions and describes an iterative method of numerical calculation for the current density of different cells. Results of computer calculations based on this model are presented.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 9 (1987), S. 393-408 
    ISSN: 0392-6737
    Keywords: Electronic properties of specific thin films
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto Sono stati realizzati film dia-SiC:H mediante glow-discharge in atmosfera Ar-SiH4-CH4 con differenti rapporti CH4/SiH4. La concentrazione di H nei film è stata determinate usando la reazione di risonanza1H(15N, αγ)12C ed il contenuto di carbonio mediante spettrometria Rutherford-backscattering. Da misure di trasmittanza e riflettanza nella zona UV-visibile-vicino IR sono state ricavate le costanti ottiche, l'indice di rifrazione, la costante dielettrica, il coefficiente di assorbimento e il gap ottico. Un esame delle bande degli spettri vibrazionali dei vari legami CH, CSi e SiH ottenuti mediante misure di trasmissione nell'IR ha fornito un'interpretazione sulla struttura dei film. Sono state anche realizzate misure di conduttività di buio e di fotoconduttività sotto illuminamento di 500 W/m2. I risultati indicano che all'aumentare del contenuto di carbonio l'indice di rifrazione diminuisce sistematicamente per tutte le lunghezze d'onda, il gap ottico aumenta, la conduttività di buio diminuisce e nella configurazione strutturale tendono a prevalere le catene contenenti il carbonio.
    Abstract: Резюме Ъыли осаждены две системы пленокa-SiC:H в атмосфере Ar-SiH4-CH4, чтобы исследовать переменного отношения CH4/SiH4 на физические свойства. Состав пленок определяется с помощью резонансных ядерных реакций и измерений обратного резерфордовского рассеяния. Также определяются оптичззкся щеяь и показатель преломления с помщяю иемерений пронисаемости в видимойультрафиолетовой-близкой инфракрасной области, конфигурацуя связи с помощью измерений инфракрасной проницаемости и удельное сопротивление и фотопроводимость с помошью єлектрических измерений в темноте м при освешении 500 Bt/M2. Полученные результаты покасывают, что с увеличением содержания углерода показатель преомления систематически уменьшается для всех длин волн, єнергетическая щель увеличивается, темновое сопротивление увеличивается, конфигурация связи становится доминирующей за счет углерод-содержащих цепочек и структура становится более разориентировнной.
    Notes: Summary Two sets ofa-SiC:H films were deposited by glow discharge in an Ar-SiH4-CH4 atmosphere to investigate the effect of a variable CH4/SiH4 ratio on the physical properties. The composition of the films was determined by resonant nuclear reaction and by Rutherford backscattering measurements, the optical gap and the index of refraction by transmissivity measurements in the visible-UV-NIR range, the bonding configuration by IR transmissivity measurements and the resistivity and the photo-conductivity by electrical measurements in the dark and under a 500 W/m2 illumination. Results indicate that with increasing carbon content the refractive index decreases systematically over all wavelengths, the energy gap increases, the dark resistivity increases, the bonding configuration becomes dominated by carbon-containing chains and the structure more disordered.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physica B: Physics of Condensed Matter 170 (1991), S. 149-152 
    ISSN: 0921-4526
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physica B: Physics of Condensed Matter 176 (1992), S. 73-77 
    ISSN: 0921-4526
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 721-726 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The a-CSiSn alloy produced by rf magnetron sputtering in SiH4, CH4, and Ar atmosphere was studied as a function of the substrate temperature. The composition of the films was determined by elastic recoil detection analysis and by Rutherford backscattering measurements, and the density was then deduced. Results of a study of optical and electrical properties and of the bonding and structure of the films indicate that with the increase of the substrate temperature, the density and the imaginary part of the dielectric constant increases, the optical gap decreases, and the dark conductivity presents a different conduction mechanism depending on the substrate temperature. A correlation between the results obtained from nuclear measurements and IR spectroscopy is presented.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 1327-1333 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Amorphous and microcrystalline silicon carbide, undoped and doped, has attracted a great attention for its optical and electrical properties. The introduction of dopant atoms in the network of amorphous films permits the control of electrical properties but it gives rise to a decreasing of the optical gap. Microcrystalline SiC:H films seem to provide films having a wide range of electrical conductivities without drastic change in the optical gap. This paper presents the results of a detailed study on the effects of boron and phosphorus doping on structural, optical, and electrical properties of a-SiC:H and μc-SiC:H films. An optical gap as high as 2.1 eV, together with a conductivity of 10−3 Ω−1 cm−1, are shown by doped μc-SiC:H.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 1730-1735 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Amorphous silicon-nitrogen, a-SiNx:Hy, thin films with optical gap in the range 2.0–5.2 eV have been deposited by 13.56 MHz ultra-high-vacuum plasma enhanced chemical vapor deposition system in SiH4+NH3 gas mixtures. Compositional, optical, dark and photoelectrical and defect characterizations have been performed in order to show that a-SiNx:Hy films can be applied in optoelectronic technology as wide band-gap semiconductor. A comparison between electronic properties of a-SiNx:Hy samples and device quality a-Si1−xCx:H films, already applied in electronic devices, has been carried out. Amorphous silicon-nitrogen films show high deposition rates, good controllability of optical gap, and electronic properties similar to high-quality silicon-carbon films. No doping effect of nitrogen atoms in tetrahedral configuration has been evidenced and spin density below 7×1017 cm−3 have been measured in a-SiNx:Hy films with optical gap as high as 5.2 eV. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 2029-2032 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The temperature dependence of the structural properties of a-SiGe:H and a-CSiGe:H films has been studied. The samples were characterized by differential scanning calorimetry, conductivity measurements, electron-spin resonance, infrared, optical, and photoacoustic spectroscopy. The disagreement of previous results of differential scanning calorimetry on hydrogenated amorphous semiconductors samples (a-Si:H and a-Ge:H) is examined and discussed. The equilibration temperature determined by the temperature dependence of dc conductivity agrees well with that of the first exothermic process detected with differential calorimetry. The second exothermic effect occurs when hydrogen evolution starts, as confirmed by electron-spin resonance and infrared spectroscopies.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 59 (1986), S. 611-618 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A detailed study of the optical properties of sputtered hydrogenated amorphous silicon films with varying hydrogen concentration is presented here. The energy dependence of the absorption coefficient is looked into, in detail, from a point of view of understanding the well known Tauc rule and the alternate relations being proposed in recent years. Spectroscopic and band-structural models like Wemple–Didomenico and Penn are then utilized to analyze the optical parameters near the band-gap region of the wavelength spectra. Extensive comparisons of our results are made with those of sputtered a-Si:H films of other workers, glow discharge prepared a-Si:H, chemically vapor deposited and evaporated a-Si, and also crystalline silicon. The similarities in the variation of the optical properties of a-Si:H with increasing hydrogen concentration (or decreasing measurement temperature) to that of crystalline silicon with decreasing measurement temperature lead us to interesting conclusions. Thus, it seems that decreasing disorder (topological or thermal) in a-Si:H is equivalent to decreasing thermal disorder in c-Si, at least as far as the disorder-optical property relationships are concerned.
    Type of Medium: Electronic Resource
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