Characterization of SnxSey / Sno2-ni prepared by spray pyrolysis for photovoltaic application
Résumé
Nickel doped tin oxide and tin monoselenide thin films were coated using spray pyrolysis.
Nickel doped tin oxide Precursor solution was prepared using a 0.05M Tin (II) Chloride
(SnCl4.2H2O) and 0.05M Nickel chloride 6-hydrate (NiCl2.6H2O) in de-ionized water and then
being added in ethanol in the ratio 1:1 to get equal proportions, followed by about 2-3 drops of
hydrochloric acid. Doping tin oxide was done using uniform concentration of (NiCl2.6H2O) of
0-10 %. Precursor solution of tin selenide SxSey was prepared using alcoholic solution
consisting of tin chloride Sncl2.2H2O and 1,1-dimethl-2-selenourea (C3H8N2Se) and then
heated while stirring and left for about a week. Samples of (SnxSey) were made in ratios of
1:0.4 to 1:1.4. Thin films of SnO2, SnO2: Ni, SnxSey and SnxSey- SnO2: Ni were deposited on
glass substrate using Spray pyrolysis at deposition temperature of 375oC. The samples of tin
selenide were characterized by measuring their optical properties using UV-VIS-NIR
spectrophotometer 3700 DUV in the range 280nm to 1200nm and were used to calculate solid
state and optical properties namely band gap (Eg), refractive index (n) and absorbance (α). The
optical band gap of deposited tin selenide ranged between 1.39-2.23ev. The sample of Sn:Se1.0
had the highest absorbance of over 46.26% and lowest transmittance of about 44.3% in the
VIS-NIR region. The optical band gap of deposited Nickel doped tin oxide ranged between
3.65-3.75ev. The sample of Nickel doped tin oxide of 2% concentration had the highest
transmittance of 86.2% and lowest absorbance of about 5.05% in the VIS-NIR region. These
properties are suitable for window and absorber layers for application in photovoltaic cell. The
diode characteristics such as short circuit current (Isc) = 1.118mA, open circuit voltage (Voc) =
0.607V, fill factor (FF) = 0.6792 and conversion coefficient (η) = 0.4609 % was obtained for
Tin selenide (SnxSey) and nickel doped tin oxide (SnO2: Ni) solar cell.