Journal Article machine learning reflectometry X-ray reflectivity data analysis Faster R-CNN GIWAXS GenX Python Review X-ray diffraction XRR all-perovskite tandem solar cells atomic force microscopy autonomous experiments beamline control closed-loop control convolutional neural networks deep learning grazing-incidence X-ray diffraction grazing-incidence wide-angle X-ray scattering inverse problems metal halide perovskites morphology neural networks neutron scattering organic semi-conductors organic semiconductors peak detection perovskite solar cells