Quantitative electron tomography investigation of a TiO2 based solar cell photoanode

Electron Microscopy and Analysis Group Conference 2013

Divitini, G.^1 ; Abrusci, A.^2 ; Di Fonzo, F.^3 ; Snaith, H.^2 ; Ducati, C.^1

Department of Materials Science and Metallurgy, University of Cambridge, CB2 3QZ Cambridge, United Kingdom^1

Clarendon Laboratory, University of Oxford, OX1 3PU Oxford, United Kingdom^2

IIT-Istituto Italiano di Tecnologia, Via Pascoli 70/3, I-20133 Milan, Italy^3

关键词: Constant thickness;    Different length scale;    Electron tomography;    Focused ion beam milling;    Nano-structured TiO2;    Nanoscale morphology;    TEM characterization;    Tomographic reconstruction;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/522/1/012063/pdf
DOI  :  10.1088/1742-6596/522/1/012063

来源: IOP

【 摘 要 】

The development of efficient thin film solar cells requires a deep knowledge of the nanoscale morphology of the active layers. While conventional investigation is usually limited to 2D information, here we use electron tomography to unravel a complex particle network in a non-ambiguous, 3D reconstruction. We present our study of a dye sensitised solar cell, based on a nanostructured TiO2photoanode produced by pulsed laser deposition (PLD) and displaying a hierarchical, quasi-1D arrangement. We prepare the sample for electron tomography using focused ion beam (FIB) milling to obtain a micro-pillar, instead of a conventional TEM lamella. This approach has the advantage of allowing higher quality tomographic reconstructions of complex morphologies due to the increased tilt range available and the constant thickness of the section. We analyse the resulting reconstruction to quantitatively investigate the geometry of the TiO2network. We compare the findings with a photoanode based on a conventional TiO2paste, determining the anisotropy of the PLD-grown film. To complement our nanoscale TEM characterization, we also employ FIB tomography, to obtain a complete structural characterisation of the photoanode at different length scales.