Omnidirectional and Highly Sensitive Microtubular Photodetectors Based on QD/2D Heterojunctions

Roll-up technology provides a feasible approach to transform patterned planar membranes into three-dimensional (3D) tubular microstructures. The tubular geometry enables the confinement of the local electromagnetic field and strengthens the photon–matter interaction inside the structure. By applying the roll-up method, we fabricated 3D tubular photodetectors from graphene/quantum dots (QDs) embedded polymer membranes around an optical fiber. These fabricated tubular photodetectors exhibit 5 times higher photoresponsivity compared to their planar counterparts. The enhanced responsivity is related to the light-trapping effect of the tubular structure as verified by the finite-difference time-domain (FDTD) simulation. 3D tubular photodetectors can detect photons accurately over a wide incidence angle (0–360°) without the responsivity decline. This unprecedented feature suppresses all published reports and lifts the restriction of the limited measured angle in conventional photodetectors. The omnidirectional and highly sensitive tubular QDs/2D-based devices, opening a route toward future optoelectronic devices from imaging to tracking solar cells.