Ilona Oja Acik
Tallinn University of Technology
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Featured researches published by Ilona Oja Acik.
Beilstein Journal of Nanotechnology | 2016
Erki Kärber; Atanas Katerski; Ilona Oja Acik; A. Mere; Valdek Mikli; Malle Krunks
Chemical spray pyrolysis (CSP) is a fast wet-chemical deposition method in which an aerosol is guided by carrier gas onto a hot substrate where the decomposition of the precursor chemicals occurs. The aerosol is produced using an ultrasonic oscillator in a bath of precursor solution and guided by compressed air. The use of the ultrasonic CSP resulted in the growth of homogeneous and well-adhered layers that consist of submicron crystals of single-phase Sb2S3 with a bandgap of 1.6 eV if an abundance of sulfur source is present in the precursor solution (SbCl3/SC(NH2)2 = 1:6) sprayed onto the substrate at 250 °C in air. Solar cells with glass-ITO-TiO2-Sb2S3-P3HT-Au structure and an active area of 1 cm2 had an open circuit voltage of 630 mV, short circuit current density of 5 mA/cm2, a fill factor of 42% and a conversion efficiency of 1.3%. Conversion efficiencies up to 1.9% were obtained from solar cells with smaller areas.
Beilstein Journal of Nanotechnology | 2014
Erki Kärber; Atanas Katerski; Ilona Oja Acik; Valdek Mikli; A. Mere; I. Sildos; Malle Krunks
Summary Solar cells consisting of an extremely thin In2S3/CuInS2 buffer/absorber layer uniformly covering planar ZnO were prepared entirely by chemical spray pyrolysis. Au nanoparticles (Au-NPs) were formed via thermal decomposition of a gold(III) chloride trihydrate (HAuCl4·3H2O) precursor by spraying 2 mmol/L of the aqueous precursor solution onto a substrate held at 260 °C. Current–voltage scans and external quantum efficiency spectra were used to evaluate the solar cell performance. This work investigates the effect of the location of the Au-NP layer deposition (front side vs rear side) in the solar cell and the effect of varying the volume (2.5–10 mL) of the sprayed Au precursor solution. A 63% increase (from 4.6 to 7.5 mA/cm2) of the short-circuit current density was observed when 2.5 mL of the precursor solution was deposited onto the rear side of the solar cell.
Nanoscale Research Letters | 2014
Atanas Katerski; Erki Kärber; Ilona Oja Acik; L. Dolgov; A. Mere; I. Sildos; Valdek Mikli; Malle Krunks
The chemical spray pyrolysis method was used to deposit CuInS2 (CIS) thin films and Au nanoparticles (NPs) in two configurations: glass/Au-NP layer covered with CuInS2 film (Au-NP/CIS) and glass/CuInS2 films covered with Au-NP layer (CIS/Au-NP). According to X-ray diffraction (XRD), the spray of 2 mM HAuCl4 aqueous solution with a volume of 2.5 to 15 ml onto a glass substrate at 340°C results in metallic Au nanoparticles with a similar mean crystallite size in the range of 30 - 38 nm. The mean crystallite sizes remain in the range of 15 - 20 nm when grown onto a CIS film. The prepared films show plasmonic light absorption with increasing intensity in the spectral range of 500- 800 nm when increasing the volume of HAuCl4 solution sprayed. When compared to bare CIS on glass, the absorptance was increased ca. 4.5 times in the case of glass/Au-NP/CIS and ca. 3 times in the case of glass/CIS/Au-NP configuration. The glass/Au-NP/CIS configuration had an advantage since Au-NP could be embedded without chemically damaging the CIS.
Archive | 2008
Malle Krunks; Atanas Katerski; T. Dedova; A. Mere; Ilona Oja Acik
Journal of Thermal Analysis and Calorimetry | 2011
Kairi Otto; Petra Bombicz; János Madarász; Ilona Oja Acik; Malle Krunks; György Pokol
Materials Science in Semiconductor Processing | 2015
Deniss Klauson; Inga Gromyko; T. Dedova; Natalja Pronina; Marina Krichevskaya; Olga Budarnaja; Ilona Oja Acik; O. Volobujeva; I. Sildos; Kathriin Utt
Materials Science in Semiconductor Processing | 2015
Merike Kriisa; Malle Krunks; Ilona Oja Acik; Erki Kärber; Valdek Mikli
Thin Solid Films | 2015
Albert Owino Juma; Ilona Oja Acik; Valdek Mikli; A. Mere; Malle Krunks
Physica Status Solidi (c) | 2016
S. Polivtseva; Ilona Oja Acik; Atanas Katerski; A. Mere; Valdek Mikli; Malle Krunks
Journal of Thermal Analysis and Calorimetry | 2009
Ilona Oja Acik; János Madarász; Malle Krunks; Kaia Tõnsuaadu; György Pokol; Lauri Niinistö