Ultrathin Silicon Nanomembrane in a Tubular Geometry for Enhanced Photodetection

Advanced 3D mesostructures have prominent applications in flexible electronics, photonics, mechanics, and biomedicine. Here, 3D tubular silicon photodetectors are demonstrated by self‐rolling ultrathin silicon nanomembranes with enhanced broadband photodetection and responsivity. Strain distributions within the unique circular structures are investigated with micro‐Raman spectroscopy, while the tensile strain of the rolled‐up microtubes can be controlled with the tube diameter by modifying the membrane thickness and etching parameters during the rolled‐up process. The tubular photodetector exhibits increased photocurrent and suppressed dark current compared with planar devices over a wide incident angle. This study provides a novel approach to construct high‐performance omnidirectional Si‐based photodetectors and offers promising prospects for design and manufacture of complex 3D optoelectronic devices.