Wyniki wyszukiwania - BazTech

1

Chemically synthesized PbS nanoparticulate thin films for a rapid NO2 gas sensor

Burungale V. V., Devan R. S., Pawar S. A., Harale N. S., Patil V. L., Rao V. K., Ma Y. R., Ae J. E., Kim J. H., Patil P. S.

Materials Science Poland

|

2016

|

Vol. 34, No. 1

204--211

EN

Rapid NO2 gas sensor has been developed based on PbS nanoparticulate thin films synthesized by Successive Ionic Layer Adsorption and Reaction (SILAR) method at different precursor concentrations. The structural and morphological properties were investigated by means of X-ray diffraction and field emission scanning electron microscope. NO2 gas sensing properties of PbS thin films deposited at different concentrations were tested. PbS film with 0.25 M precursor concentration showed the highest sensitivity. In order to optimize the operating temperature, the sensitivity of the sensor to 50 ppm NO2 gas was measured at different operating temperatures, from 50 to 200 degrees C. The gas sensitivity increased with an increase in operating temperature and achieved the maximum value at 150 degrees C, followed by a decrease in sensitivity with further increase of the operating temperature. The sensitivity was about 35 % for 50 ppm NO2 at 150 degrees C with rapid response time of 6 s. T90 and T10 recovery time was 97 s at this gas concentration.

2

Structural and optical characteristics of SnS thin film prepared by SILAR

Mukherjee A., Mitra P.

Materials Science Poland

|

2015

|

Vol. 33, No. 4

847--851

EN

SnS thin films were grown on glass substrates by a simple route named successive ion layer adsorption and reaction (SILAR) method. The films were prepared using tin chloride as tin (Sn) source and ammonium sulfide as sulphur (S) source. The structural, optical and morphological study was done using XRD, FESEM, FT-IR and UV-Vis spectrophotometer. XRD measurement confirmed the presence of orthorhombic phase. Particle size estimated from XRD was about 45 nm which fitted well with the FESEM measurement. The value of band gap was about 1.63 eV indicating that SnS can be used as an important material for thin film solar cells. The surface morphology showed a smooth, homogenous film over the substrate. Characteristic stretching vibration mode of SnS was observed in the absorption band of FT-IR spectrum. The electrical activation energy was about 0.306 eV.

3

Optymalizacja warunków otrzymywania kropek kwantowych metodą SILAR

Trenczek-Zając A., Łącz A., Ziąbka M., Radecka M.

Materiały Ceramiczne

|

2014

|

T. 66, nr 1

49--54

PL

W celu otrzymania kropek kwantowych PbS i CdS zastosowano metodę adsorpcji kolejnych warstw jonów i reakcji (SILAR) z wykorzystaniem roztworów siarczku(II) sodu, azotanu(V) ołowiu(II) i siarczanu(VI) kadmu na bazie wody destylowanej lub metanolu. Zastosowano stężenia z zakresu 0,001-0,1 M oraz liczbę cykli osadzania zmieniającą się w granicach 5-15. Obecność poszczególnych pierwiastków w otrzymanych strukturach potwierdzona została analizą widma EDS. Na podstawie wyników XRD stwierdzono, że zarówno PbS jak i CdS krystalizują w układzie regularnym. Analiza zdjęć otrzymanych metodą SEM pozwoliła na określenie zależności pomiędzy parametrami procesu SILAR, takimi jak stężenie roztworów prekursorów, liczba cykli osadzania i rodzaj rozpuszczalnika, a rozmiarem nanostruktur PbS i CdS. W przypadku obu siarczków, zastosowanie roztworów wodnych prekursorów o stężeniu nie przekraczającym 0,01 M stwarza warunki do krystalizacji pojedynczych kropek kwantowych, których rozmiar rośnie wraz ze wzrostem stężenia. Analogiczne zależności obserwowane są w przypadku zwiększania liczby cykli, bez względu na rodzaj rozpuszczalnika. Stosowanie roztworów wodnych o większym stężeniu (≥ 0,1 M) prowadzi do częściowej aglomeracji. Zmiana rozpuszczalnika na metanol pozwala na zmniejszenie rozmiaru nanostruktur.

EN

In order to deposit quantum dots of PbS and CdS successive ionic layer adsorption and reaction, SILAR route was employed. Water- and methanol-based solutions of sodium sulfide(II), lead(II) nitrate and cadmium sulfate were used. A concentration of solutions varied from 0.001-0.1 M and a number of cycles changed from 5-15. The EDS analysis confirmed the presence of sulphur and lead or cadmium in the obtained structures. Based on the XRD results it was found that both PbS and CdS crystallizeed in the cubic structure. SEM images allowed us to determine the relationship between size of deposited QDs and SILAR parameters such as the solution concentration, the number of cycles and the solvent type. In the case of both sulphides, deposition from the water-based solutions of concentrations up to 0.01 M creates the conditions suitable for crystallization of individual QDs. Along with the increase in the solution concentration the size of QDs increases. Similar effects are observed in case of the increase in the number of cycles regardless of the solvent type. The usage of more concentrated solutions (≥ 0.1 M) leads to partial agglomeration. Changing the solvent to methanol leads to smaller nanostructures.

4

Optimization of deposition temperature of SILAR Cu-rich CuInS2 thin films

Maheswari B., Dhanam M.

Materials Science Poland

|

2013

|

Vol. 31, No. 2

193--200

EN

CuInS2 (CIS) is studied widely as a promising absorber material for high efficient and low cost thin film solar cells. CIS thin films are prepared on soda lime glass substrates using Successive Ionic Layer Adsorption and Reaction (SILAR) technique at different deposition temperatures (40 to 70 °C). The structural, compositional and optical properties are studied with x-ray diffractometer, energy dispersive x-ray analyzer and spectrophotometer. The influence of the deposition temperature on the properties of CIS thin films is discussed in this paper in detail.

5

Hydrogen and LPG sensing properties of SnO2 films obtained by direct oxidation of SILAR deposited SnS

Mitra P., Mondal S.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2008

|

Vol. 56, nr 3

294-312

EN

Hydrogen (H2) and liquid petroleum gas (LPG) sensing properties of SnO2 thin films obtained by direct oxidation of chemically deposited SnS films has been studied. The SnS film was prepared by a chemical technique called SILAR (Successive Ionic Layer Adsorption and Reaction). The sensor element comprises of a layer of chemically deposited SnO2 film with an overlayer of palladium (Pd) sensitiser. The Pd sensitiser layer was also formed following a chemical technique. The double layer element so formed shows significantly high sensitivity to H2 and LPG. The temperature variation of sensitivity was studied and the maximum sensitivity of 99.7% was observed at around 200°C for 1 vol% H2 in air. The response time to target gas was about 10 seconds and the sensor element was found to'recover to its original resistance reasonably fast. The maximum sensitivity of 98% for 1.6 vol% LPG was observed at around 325°C. The sensor response and recovery was reasonably fast (less than one minute) at this temperature.