SnSe2/TiO2 heterostructures for broadband photodetection

The formation of heterojunctions presents a novel architecture for photodetector applications, offering an expanded active surface area that enhances light absorption and overall performance. Recently, metal-dichalcogenides have attracted significant interest for future optoelectronic devices due to their exceptional electronic and optical properties . However, their application has been limited to narrow detection ranges. To overcome this, broadband photodetection can be achieved through the combination of two distinct materials in a heterostructure. Among these, SnSe 2 has gained significant attention as a promising material for next-generation optoelectronics . In this work, a vertical heterostructure formed by integrating SnSe 2 with hydrothermally grown TiO 2 nanorods . The TiO 2 nanorods , which were uniformly distributed across the surface, were synthesized using a hydrothermal method , while the SnSe 2 layer was deposited via thermal evaporation . This configuration increases the junction area of the heterostructure, enhancing its performance across a broad spectral range (400–800 nm). Upon 325 nm incidence, the SnSe 2 /TiO 2 heterostructure demonstrates a remarkable high responsivity of 34.63 mA/W and a detectivity of 10 7 Jones. This significantly enhanced optoelectronic performance of the SnSe 2 /TiO 2 heterostructure offers great potential for the development of efficient broadband photodetectors. • SnSe 2 /TiO 2 heterostructure thin films were fabricated at room temperature using thermal evaporation method and hydrothermal method respectively followed by different annealing temperatures under vacuum. • The TiO 2 nanorods film exhibit uniform distribution of rods like structures across the FTO substrate. • The SnSe 2 /TiO 2 heterostucture device annealed at 150 °C shown the response speed of τ r = 2.230 s and τ f = 0.754 s under 0 V bias. • The heterostructure device shown the responsivity of 34.63 × 10 −3 AW −1 and the highest detectivity of 2.44 × 10 7 Jones for the film annealed at 150 °C at a bias of −0.5 V.