Infiltration and Selective Interactions at the Interface in Polymer-Oxide Hybrid Solar Cells

16th International Conference on Positron Annihilation

Ferragut, R.^1,2 ; Aghion, S.^1,2 ; Moia, F.^1,2 ; Binda, M.^3 ; Canesi, E.V.^3 ; Lanzani, G.^3 ; Petrozza, A.^3

LNESS, Dipartimento di Fisica, Politecnico di Milano, via Anzani 42, 22100 Como, Italy^1

Istituto Nazionale di Fisica Nucleare, Via Celoria 16, 20133 Milan, Italy^2

Center for Nano Science and Technology at Polimi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, 20133 Milan, Italy^3

关键词: Coincidence doppler broadening;    Device performance;    Hybrid solar cells;    Implantation energies;    Nanoporous structures;    Poly-3-hexylthiophene;    Quantitative evaluation;    Selective interaction;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/443/1/012051/pdf
DOI  :  10.1088/1742-6596/443/1/012051

来源: IOP

【 摘 要 】

Positron annihilation spectroscopy was used to characterize polymer-based hybrid solar cells formed by poly(3-hexylthiophene) (P3HT) finely infiltrated in a porous TiO2skeleton. A step-change improvement in the device performance is enabled by engineering the hybrid interface by the insertion of a proper molecular interlayer namely 4-mercaptopyridine (4-MP). In order to obtain depth-resolved data, positrons were implanted in the sample using a variable-energy positron beam. The characteristics of the partially filled nanoporous structures were evaluated in terms of the depth profile of the positronium yield and the S-parameter. A quantitative evaluation of the pore filling in the deep region is given from the analysis of Coincidence Doppler Broadening taken at fixed implantation energy. We note a remarkable difference in terms of the positronium yield when the 4-MP interlayer is introduced, which means a better covering of P3HT on the porous surface.