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Spray process under different applied voltages (0 V to 700 V) is used for the deposition of poly (3, 4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT:PSS) hole transport layer (HTL). The deposition of PEDOT:PSS film by spray process under the effect of electric field results in smoother film morphology, increase in conductivity and reduction in the sheet resistance. The improvement in surface morphology and conductivity enhancement of PEDOT: PSS films are the key to the improvement in the J-V characteristics of ITO/PEDOT:PSS/P3HT:PCBM/Al solar cell structures. The XPS peak height for PEDOT at 164.4 eV increased by 47% and that for PSS at 169.0 eV decreased by 30%, showing that the enhancement in the conductivity of the films deposited under electric field is due to the change in the PEDOT: PSS ratio. The organic solar cell using the electric field (created using 700 V) assisted spray deposited PEDOT:PSS film exhibit 42% and 69% improvement in the short circuit current density(Jsc) and power conversion efficiency, respectively, in comparison to the cells having PEDOT:PSS films deposited without the electric field. [ABSTRACT FROM AUTHOR]

Kesterite (Cu 2 ZnSnS 4 ) thin films are spray deposited under 0 V and 1500 V DC voltages and then treated with N 2 +H 2 S(5%) environment at 500 °C for 1 h for sulphurisation. The improvement in different properties like structural, optical, morphological and electrical occur in the kesterite films deposited under the electric field. The activation energy is also reduced for these films, after applying the DC voltage during the spray deposition. These improvements resulted in the enhancement of the catalytic properties of kesterite films for use as the counter electrodes in dye sensitized solar cells. Dye sensitized solar cell using the kesterite film as a counter electrode deposit under the applied voltage of 1500 V exhibits the power conversion efficiency of 4.93%, which is higher than that for the kesterite film deposit under the applied voltage = 0 V (3.77%). The power conversion efficiency of sulphurised kesterite films deposit at 0 V and 1500 V yield further improvement in the power conversion efficiency (6.58 and 7.67%, respectively). [ABSTRACT FROM AUTHOR]

Abstract: Spray process under an electric field was used for the deposition of zinc oxide (ZnO) electron transport layer by applying a DC voltage to the nozzle in order to make the layer smoother, highly crystalline and defect free having good electrical and optical properties. The nanostructure formed differed from that in the spray deposited ZnO layer without applying any voltage. The photovoltaic performance of the inverted organic solar cells (IOSC – ITO/ZnO/P3HT:PCBM/Ag) made using the nanostructured layer (deposited with the applied voltage=1000V) and the cell stability were found to improve in comparison with the devices made using the nanostructured layer with the applied voltage=0V. A change in the surface morphology of ZnO layer occurred with time and its effect on the cell performance was investigated. Photoluminescence (PL) spectra as well as XPS spectra showed that defects related mainly to oxygen vacancies were reduced in the spray deposited ZnO layer with the applied voltage=1000V. This resulted in a higher IOSC efficiency (~2.7%) and good stability for a long duration (~105 days) with only 20% degradation in PCE. On the other hand, there was a 46% degradation in PCE of IOSC using spray deposited ZnO layer without applying voltage. [Copyright &y& Elsevier]