| SM ISO690:2012|
VATAVU, Sergiu; VON MORZE, Natascha; WIESNER, Sven; HINRICHS, V.; LUX-STEINER, MarthaCh.; RUSU, Marin. CuInSe2 nanostructures for hybrid photovoltaics. In: Materials Science and Condensed Matter Physics. Editia a 8-a, 12-16 septembrie 2016, Chişinău. Chişinău: Institutul de Fizică Aplicată, 2016, p. 280. ISBN 978-9975-9787-1-2.
|Materials Science and Condensed Matter Physics
Editia a 8-a, 2016
Conferința "International Conference on Materials Science and Condensed Matter Physics" |
8-th Edition, Chişinău, Moldova, 12-16 septembrie 2016
High efficiency photovoltaic (PV) converters’ development brought into light the possibility of inorganic and organic materials joined use. The concept of benefitting both from the best properties of inorganic and organic materials is being investigated in hybrid devices. Organic materials use in PV still do exhibit problems related to excitonic diffusion length, low mobility of charge carriers and morphology of the resulting structure . The right combination of organic/inorganic structures might result in PV nanostructures, having higher conversion efficiencies  than conventional organic solar cells. The choice of the inorganic counterpart in a hybrid device might tune the absorption spectra, crucial for a solar cell. CuInSe2, has already being known as a highly investigated thin film PV material, shows its perspective for the use in nanostructured hybrid solar cells leaving plenty of room for nanoscale device research. Compositional variations of CuInSe2 are investigated for nanostructures prepared by Chemical Close-Spaced Vapor Transport (CCSVT) and Metal Organic Chemical Vapour Deposition (MOCVD) methods. CuInSe2 both nanostructures and thin films have been deposited on Mo/NaBarrier/Glass substrates. In2Se3 powder (99.999%) has been used as source material. Cu thin films (6-250 nm thick) and Cu nanoparticles have been used as precursors. A 10:1 ratio of HCl and H2 flows have been used to volatilize indium selenide at a source temperature of 550°C. MOCVD CuInSe2 nanostructures have been prepared on Mo/Na-barrier/glass substrates using the precursors: Cyclopentadienyl (triethylphosphine) Copper (I) (C5H5)CuP(C2H5)3, Trimethylindium & N, N Dimethyldodecylamine C14H31N(CH3)3In, and Ditertiarybutylselenide Se(C4H9)2. A substrate temperature of 500°C has been kept steady for all processes. The [Cu]/[In] precursor flow ratio has been varied in the range of 0.612 to 1.708. Structural analysis, involving X-ray diffraction, has been carried out in θ -2 θ and grazing incidence (0.1°-1.1°) device configurations. The elemental composition of the as-prepared CuInSe2nanostructures were analyzed by Laser Ablation Inductively Coupled Plasma Mass-Spectrometry (LA-ISP-MS). Surface morphology and cross-section views have been analyzed on a scanning electron microscope system. X-ray Fluorescence analysis has been carried out as well whereappropriate. CuInSe2 phase ((101), (112), (204)/(220), (116)/(332)) is detected in both types of sampled prepared (thin films and nanostructures) by CCSVT method. Depending on the Cu precursor used (Cu thin films or Cu nanoparticles), CuInSe2 thin films (0.1-2.0 µm thick) or nanostructures (max. height in the range of 30-170 nm for Cu nanoparticle precursor used: diameter and height of Cu nanoparticles varied depending on the deposition time as 40-60 nm and 30-90 nm respectively) suitable for hybrid PV devices have been prepared. The presence of excess of Selenium detected by LA-ISP-MS and the presence of low intensity unidentified peaks detected by the structural characterization might be attributed to Molybdenum Selenide compound presence. Structural and LA-ICP-MS characterizations have proven that the optimum precursor flow ratio in MOCVD system is 0.977 [Cu]/[In] for preparation of single phase CuInSe2 ((101), (112), (204)/(220), (116)/(332)) nanostructures (10 and 20 nm high). The phase composition tuning is achived by MOCVD recipe and post deposition treatment in Selenium and Hydrogen containing ambients. The authors gratefully acknowledge the support of the Helmholtz-Gesellschaft Deutscher Forschungszentren e.V. (HGF) under the project “Hybrid-PV”.