Flexible Self-Powered Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXene Nanosheet/CdS Nanobelt Photodetector with Enhanced Responsivity and Photosensitivity
Muhammad Zubair Nawaz, Asad Khaleeq, Waqar ul Hasan, Waqas Ahmad, Rana Zafar Abbas Manj, Muhammad Shahrukh Saleem, Inaam Ullah, Ayesha Irfan, Israr Masood ul Hasan, Muhammad Yaqub, H. M. Noor ul Huda Khan Asghar, Gul Naz, Mai Li, Chunrui Wang, Yu. Yu. Illarionov
Abstract
Can the semimetallic 2D Ti 3 C 2 T x MXene function as an active photosensitive material rather than merely an electrode? Can a flexible, self-powered photodetector based entirely on 2D and 1D photoactive materials overcome the persistent challenge of high dark current that often limits low-light detection? Addressing these questions, we report a flexible self-driven photodetector constructed from a 2D Ti 3 C 2 T x MXene and a 1D CdS nanobelt heterojunction, where both constituents actively contribute to low-light detection. Unlike conventional approaches where MXene serves as a passive electrode, Ti 3 C 2 T x here plays an active role in photogeneration and charge separation. The 2D-1D architecture facilitates the formation of a strong built-in electric field across the interface, promoting efficient photocarrier extraction while significantly suppressing dark current. The device achieves an exceptional light-to-dark current ratio exceeding ≈10 5, a high responsivity of ≈34.42 A/W, and detectivity up to ≈5.68 × 10 14 Jones, along with a rapid response time of ≈7.2/120 μs under zero bias. These results highlight the potential of MXene-based heterostructures in advancing high-performance, low-light, self-powered optoelectronic platforms.