Step-Graded III–V Metamorphic Buffers on Ge for High-Efficiency Photovoltaics: Investigation of Strain Relaxation and Morphology Evolution. - Achilli, Elisabetta; Armani, Nicola; Pedrini, Jacopo; Greco, Erminio; Digrandi, Salvatore; Fratta, Andrea; Pezzoli, Fabio; Campesato, Roberta; Timò, Gianluca (Crystals (2073-4352), 2025)