CHEMICALLY DEPOSITED HETEROJUNCTION SOLAR CELLS Pb(1-x)Cd(x)S(n)/Si(p)

2010 ◽  
Vol 09 (06) ◽  
pp. 599-604 ◽  
Author(s):  
OUNISSI ABDELHAMID ◽  
OUDDAI NADIA

The fimls of Pb (1-x) Cd (x) S have been prepared on glass substrates by chemical method. The optical study of transmission T(λ) and reflexion R(λ) spectra has enabled us to determine the compounds whose gap is close to 1.5 eV. The heterojunction is obtained by the chemical deposition of the Pb (1-x) Cd (x) S films grown on the p-type Silicon substrates (7 Ω cm). The preparation conditions of the ternary compound whose gap is 1.48 eV have been used to achieve the heterojunction Pb (1-x) Cd (x) S - n/Si - p , and we have studied the effect of thermal treatment on the prepared heterojunction. X-ray diffraction has been used to determine the variation of the crystalline parameter, the ratio of cadmium in the compound Pb (1-x) Cd (x) S and the dependence of the gap on the cadmium composition. C–V characteristics were examined to understand the average concentration of impurities in the compound Pb (1-x) Cd (x) S .

1998 ◽  
Vol 76 (11) ◽  
pp. 1707-1716 ◽  
Author(s):  
I Coulthard ◽  
S Degen ◽  
Y -J Zhu ◽  
T K Sham

Utilizing porous silicon as a reducing agent and a substrate, gold complex ions [AuCl4]- were reduced from aqueous solution to produce nanoparticles of gold upon the surface of porous silicon. Scanning electron microscopy (SEM) was utilized to study the morphology of the porous silicon layers and the deposits of gold nanoparticles. It is found that preparation conditions have a profound effect on the morphology of the deposits, especially on porous silicon prepared from a p-type wafer. The gold nanoparticles, varying from micrometric aggregates of clusters of the order of 10 nm, to a distribution of nearly spherical clusters of the order of 10 nm, to strings of ~10 nm were observed and compared to bulk gold metal using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS). These techniques confirm and complement the SEM findings. The potential for this reductive deposition technique is noted.Key words: gold nanostructures, reductive deposition, porous silicon, morphology, X-ray spectroscopy.


2013 ◽  
Vol 690-693 ◽  
pp. 1659-1663
Author(s):  
Hai Fang Zhou ◽  
Xiao Hu Chen

The preparation and characterization of CuInS2 thin films on ITO glass substrates prepared by one-step electrodeposition have been reported. Samples were characterized using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). The results indicate that CuInS2 is the major phase for the film deposited at -1.0 V, after annealing at 550°C in sulfur atmosphere, and the sample is Cu-rich and p-type semiconductor. Additionally, the energy band gap and carrier concentration for the sample were found to be 1.43 eV and 4.20×1017 cm−3, respectively. Furthermore, the maximum photocurrent density of the sample was found to be -1.15 mA/cm2 under 255 lx illumination, the sample shows the photo-enhancement effect.


2009 ◽  
Vol 60-61 ◽  
pp. 11-15 ◽  
Author(s):  
Pe Min Lu ◽  
Hong Jie Jia ◽  
Shu Ying Cheng

SnS and Ag films were deposited on glass substrates by vacuum thermal evaporation successively, then they were annealed in N2 ambience at a temperature of 300 oC for 2h. By controlling the Ag evaporation voltage to roughly alter content of Ag in SnS films, different Ag-doped SnS films were obtained. The microstructures, composition and properties of the films were characterized with X-ray diffraction ( XRD ), atomic force microscopy(AFM) and some other methods. With the increase of Ag evaporation voltage (VAg), there exist new phases of Ag8SnS6 and Ag2S, whose intensity of diffraction peaks increases with the increasing Ag-dopant, and the average roughness of the films varies from 18.7nm to 23.6nm, and grain size increases from 192nm to 348nm. With the increase of VAg, the evaluated direct band gap Eg of the films decreases from 2.28eV(undoped) to 2.05eV (VAg=70V), the carrier concentration value and Hall mobility of the films diminishes from 2.048×1014cm-3 and 25.96 cm2.v-2.s-1 to 1.035×1016 cm-3 and 5.66 cm2.v-2.s-1, respectively; while the resistivity of the films decreases sharply from 1174Ω.cm(undoped ) to 107Ω.cm (VAg=70V ). All the films are of p-type conductivity. The above results show that the semiconducting properties of the SnS films have been improved by silver-doping.


2019 ◽  
Vol 963 ◽  
pp. 485-489
Author(s):  
Monia Spera ◽  
Giuseppe Greco ◽  
Raffaella Lo Nigro ◽  
Salvatore di Franco ◽  
Domenico Corso ◽  
...  

This paper reports on the formation and characterization of Ohmic contacts to n-type and p-type type 3C-SiC layers grown on silicon substrates. In particular, Ohmic contact behavior was obtained either using Ni or Ti/Al/Ni layers annealed at 950°C. The values of the specific contact resistance ρc estimated by means of circular TLM (C-TLM) structures varied in the range ~ 10-3-10-5 Ωcm2, depending on the doping level of the 3C-SiC layer. A structural analysis performed by X-Ray Diffraction (XRD) allowed to identify the main phases formed upon annealing, i.e., Ni2Si and Al3Ni2. The morphology of the reacted contacts depended on that of the underlying substrate. The results can be useful for the development of a variety of devices on the cubic 3C-SiC polytype.


2020 ◽  
Vol 10 (5) ◽  
pp. 6161-6164
Author(s):  
S. M. Ho

Ternary compounds such as Cu4SnS4 thin films can be deposited onto glass substrates by various deposition methods: electrodeposition, chemical bath deposition, successive ionic layer adsorption and reaction, and evaporation techniques. Cu4SnS4 films could be used in solar cell applications because of their suitable band gap and large absorption coefficient. This paper reviews previous researches on Cu4SnS4 thin films. X-ray diffraction showed that the obtained films are orthorhombic in structure and polycrystalline in nature. Cu4SnS4 films exhibited p-type electrical conductivity and indicated band gap values in the range of 0.93 to 1.84eV.


Author(s):  
T. Joseph Sahaya Anand ◽  
Rajes K. M. Rajan ◽  
Md Radzai Said ◽  
Lau Kok Tee

Thin films of nickel chalcogenide, NiX2 (X= Te, Se) have been electrosynthesized on indium-tin-oxide (ITO) coated glass substrates. The films were characterized for their structural, morphological and compositional characteristics. Consisting of transition metals and chalcogenides (S, Se and Te), they show promising solar absorbent properties such as semiconducting band gap, well adhesion to substrate and good conversion with better cost-effective. Cyclic voltammetry experiments have been done prior to electrodeposition in order to get the electrodeposition potential range where the observable reduction range is between -0.9-(-1.1) V. Their optical and semiconducting parameters were also analysed in order to determine the suitability of the thin films for photoelectrochemical (PEC) / solar cell applications. Structural analysis via X-ray diffraction (XRD) analysis reveals that the films are polycrystalline in nature. Scanning electron microscope (SEM) studies reveals that the films were adherent to the substrate with uniform and pin-hole free. Compositional analysis via energy dispersive X-ray (EDX) technique confirms the presence of Ni, Te, and Se elements in the films. The optical studies show that the films are of direct bandgap. Results on the semiconductor parameters analysis of the films showed that the nature of the Mott-Schottky plots indicates that the films obtained are of p-type material.


2014 ◽  
Vol 11 (3) ◽  
pp. 1257-1260
Author(s):  
Baghdad Science Journal

In this work the effect of annealing temperature on the structure and the electrical properties of Bi thin films was studied, the Bi films were deposited on glass substrates at room temperature by thermal evaporation technique with thickness (0.4 µm) and rate of deposition equal to 6.66Å/sec, all samples are annealed in a vacuum for one hour. The X-ray diffraction analysis shows that the prepared samples are polycrystalline and it exhibits hexagonal structure. The electrical properties of these films were studied with different annealing temperatures, the d.c conductivity for films decreases from 16.42 ? 10-2 at 343K to 10.11?10-2 (?.cm)-1 at 363K. The electrical activation energies Ea1 and Ea2 increase from 0.031 to 0.049eV and from 0.096 to 0. 162 eV with increasing of annealing temperature from 343K to 363K, respectively. Hall measurements showed that all the films are p-type.


2011 ◽  
Vol 10 (04n05) ◽  
pp. 749-753
Author(s):  
S. V. JAGADEESH CHANDRA ◽  
D. S. PARK ◽  
S. UTHANNA ◽  
CHEL-JONG CHOI ◽  
A. GURUVA REDDY

RF magnetron sputtering technique was employed for deposition of tantalum oxide films on p-type silicon substrates by sputtering of pure tantalum oxide target in the presence of oxygen and argon gases at a temperature of 303 K. X-ray photoelectron spectroscopic and X-ray diffraction studies indicated that the films annealed at 773 K were stoichiometric and polycrystalline respectively. The accumulation capacitance for the devices in a structure of Al/Ta2O5/p-Si has been decreased noticeably lower values for the devices annealed at high temperatures. Improved current–voltage characteristics were observed for all annealed devices with Poole–Frenkel conduction mechanism.


Author(s):  
U. Aebi ◽  
R. Millonig ◽  
H. Salvo

To date, most 3-D reconstructions of undecorated actin filaments have been obtained from actin filament paracrystal data (for refs, see 1,2). However, due to the fact that (a) the paracrystals may be several filament layers thick, and (b) adjacent filaments may sustantially interdigitate, these reconstructions may be subject to significant artifacts. None of these reconstructions has permitted unambiguous tracing or orientation of the actin subunits within the filament. Furthermore, measured values for the maximal filament diameter both determined by EM and by X-ray diffraction analysis, vary between 6 and 10 nm. Obviously, the apparent diameter of the actin filament revealed in the EM will critically depend on specimen preparation, since it is a rather flexible supramolecular assembly which can easily be bent or distorted. To resolve some of these ambiguities, we have explored specimen preparation conditions which may preserve single filaments sufficiently straight and helically ordered to be suitable for single filament 3-D reconstructions, possibly revealing molecular detail.


2009 ◽  
Vol 1 (2) ◽  
pp. 18-20
Author(s):  
Dahyunir Dahlan

Copper oxide particles were electrodeposited onto indium tin oxide (ITO) coated glass substrates. Electrodeposition was carried out in the electrolyte containing cupric sulphate, boric acid and glucopone. Both continuous and pulse currents methods were used in the process with platinum electrode, saturated calomel electrode (SCE) and ITO electrode as the counter, reference and working electrode respectively. The deposited particles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that, using continuous current deposition, the deposited particles were mixture of Cu2O and CuO particles. By adding glucopone in the electrolyte, particles with spherical shapes were produced. Electrodeposition by using pulse current, uniform cubical shaped Cu2O particles were produced


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