Prospects for electron microscopy characterisation of solar cells: Opportunities and challenges

Several electron microscopy techniques available for characterising thin-film solar cells are described, including recent advances in instrumentation, such as aberration-correction, monochromators, time-resolved cathodoluminescence and focused ion-beam microscopy. Two generic problems in thin-film solar cell characterisation, namely electrical activity of grain boundaries and 3D morphology of excitionic solar cells, are also discussed from the standpoint of electron microscopy. The opportunities as well as challenges facing application of these techniques to thin-film and excitonic solar cells are highlighted.