Atomic bonding-engineered heterogeneous integration of semiconductor nanowires by femtosecond laser irradiation for a miniaturized photodetector

Abstract

Heterogeneous integration of semiconductor nanowires (NWs) incorporating the advantages of various materials is vital for developing new generation nanoscale devices. To date, the integration issues, especially the atomic bonding integration, remain a grand challenge due to the high melting point and lattice mismatches of heterogeneous materials. Herein, atomic bonding-engineered heterogeneous integration of semiconductor NWs is successfully achieved based on femtosecond (fs) laser irradiation. The nanobraze-welding mechanism is revealed for the formation of atomic-level bonding between CuO and ZnO NWs. A laser irradiation-induced diffusion region is observed at the CuO/ZnO hetero-interface, which remarkably broadens the carrier transport channels to optimize the electrical properties of the CuO/ZnO NWs p-n junction. Further simulation and band gap calculation reveal the absorption of laser energy via single-photon excitation in CuO NWs and two-photon excitation in ZnO NWs. A high-performance photodetector based on laser-nanobrazed CuO/ZnO NWs p-n junction is fabricated, which exhibits a high responsivity (9.86 A/W), fast rise and decay time (0.560 s and 2.056 s). This semiconductor NWs atomic-level bonding integration may inspire the widespread application of 1D nanomaterials and reveals a prospective pathway to develop miniaturized and multi-functional electronic devices by semiconductor NWs integration.