We present the optical modelling of a mesoporous fibre perovskite solar cell (PSC). It was conducted by means of the transmission line method (TLM), which was used to calculate the efficiency and short-circuit photo-current density of the cell. The TLM was first applied for a planar mesoporous PSC and verified with the experimental results from the literature. Numerical calculations for both planar and fibre PSC were conducted and analysed regarding their efficiency in terms of optical simulation. The importance of choosing the thin-film layers’ materials and thickness was demonstrated, and a potential improvement using anti-reflection coatings was also examined.

This article addresses the phenomenon of the decreased absorption of γ-radiation when the thickness of the absorber equals a multiple of the mean free path, as observed in relevant laboratory experiments with various absorbing materials. This phenomenon can be compared with the periodic peaks in intensity in an open-ended sound tube that appear at multiples of half wavelength. This could suggest that there is analogy between the two physical systems that are the γ-ray absorber and the sound wave resonance tube. More similarities between the two systems are also presented.