Morphological and Compositional (S)TEM Analysis of Multiple Exciton Generation Solar Cells

Electron Microscopy and Analysis Group Conference 2015

Wisnivesky-Rocca-Rivarola, F.^1 ; Davis, N.J.L.K.^2 ; Bohm, M.^2 ; Ducati, C.^1

Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge

CB3 0FS, United Kingdom^1

Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge

CB3 0HE, United Kingdom^2

关键词: Chemical compositions;    Cross sectional image;    Electron hole pairs;    Multiple exciton generations;    Optical and electronic properties;    Power conversion efficiencies;    Semiconductor nanocrystals;    Structure and orientation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/644/1/012025/pdf
DOI  :  10.1088/1742-6596/644/1/012025

来源: IOP

【 摘 要 】

Quantum confinement of charge carriers in semiconductor nanocrystals produces optical and electronic properties that have the potential to enhance the power conversion efficiency of solar cells. One of these properties is the efficient formation of more than one electron-hole pair from a single absorbed photon, in a process called multiple exciton generation (MEG). In this work we studied the morphology of nanocrystal multilayers of PbSe treated with CdCl2using complementary imaging and spectroscopy techniques to characterise the chemical composition and morphology of full MEG devices made with PbSe nanorods (NRs). IN the scanning TEM (STEM), plan view images and chemical maps were obtained of the nanocrystal layers, which allowed for the analysis of crystal structure and orientation, as well as size distribution and aspect ratio. These results were complemented by cross-sectional images of full devices, which allowed accessing the structure of each layer that composes the device, including the nanorod packing in the active nanocrystal layer.