The Role of Random Texture Scattering on the Absorptance Enhancement in Halide Perovskite Layers

In this contribution, absorption enhancements due to nano-rough but also micro-rough substrates with or without additional gold coating are evaluated from the point of gains in photocurrent and from the point of view of valid optical models. We find that light trapping from nanotextured substrates follows mainly Yablonovitch model leading to an apparent shift of absorption edge. This contrasts with micro-rough substrates and also the remarkable efficient light trapping capabilities of bare layers due to their native surface roughness, where the path enhancement in this case is almost uniform, making the layer optically thicker by factor two or more.