Flexible perovskites single-crystal devices can be realized with designed crystal morphology, orientation, thickness, size, and graded band structure.

THz precision spectroscopy is a hot research topic. We present a metrological-grade hybrid dual comb spectrometer merging the high emitted power of a THz-QCL frequency comb, with the accuracy and absolute frequency scaling of an optically rectified THz comb, locked against a frequency reference.