Microgravity-activated high-performance van der Waals InSe ferroelectric semiconductor

The space microgravity environment, scarcely attainable on Earth, is considered to have a positive effect on crystal growth, especially the van der Waals layered materials with low interlayer sliding energy barriers. Here, we investigate the structure and optical/electrical properties of van der Waals InSe semiconductor cultivated in microgravity environment on China space station. Atomic-level microstructure analyses reveal that this unique environment can successfully annihilate the naturally-existing stacking faults in flexible InSe, directly activating the intrinsic sliding ferroelectricity with excellent retention stability. The corresponding ferroelectric semiconductor field-effect transistors present obviously large non-volatile memory window, high on/off ratio and excellent mobility. More essentially, they can also give superior amplified spontaneous emission with exceptionally low excitation thresholds of photons for near infrared nonlinear light sources. These findings not only present an unconventional strategy for achieving high-quality van der Waals layered single crystals like InSe but also highlight their potential for next-generation emitter-integrated computing architectures combining memory and sensor functions.