Challenges and opportunities for the characterization of electronic properties in halide perovskite solar cells

Characterisation of the electronic properties of halide perovskites is often a dilemma for researchers. Many of the data analysis methods for the most common techniques in semiconductor device physics have a small validity window or are generally only applicable to classical doped semiconductors. As alternative data analysis approaches are often prohibitively complicated and require numerical simulations of electronic and often ionic charge carriers, the analysis of data is performed qualitatively and comparatively. The overarching idea is that even if data analysis methods do not apply to a given sample, the trend should still be maintained. However, even this last statement may not be correct in certain situations. Hence, the present review provides a summary of the canonical, frequently used methods to characterise electronic properties in halide perovskites and provides a short explanation of the pitfalls in applying the method, as well as the opportunities that arise from using these methods in ways that are not yet common in the current literature.