A route towards enhanced UV photo-response characteristics of SnO2/p-Si based heterostructures by hydrothermally grown nanorods

Integrating nanorods (NRs) into the structure of p-n heterojunction-based devices proposes a promising approach to overcome limited light absorption and charge transfer in optoelectronic devices. Herein, a new design scheme is demonstrated to improve the UV photo response properties of the heterojunction photodiodes. This design contains a spin-coated SnO2 thin film underneath hydrothermally grown SnO2 NRs. The NRs play versatile roles in enhancing the light trapping and providing direct pathway for electron transport, while thin film provides vertically aligned NRs formation and high-quality junction creation. The resulting structure offers an improvement in light harvesting and photo response characteristics of the devices. A photoresponsivity of 110 mA/W and a photosensitivity of 5.3 are observed in SnO2-NRs/SnO2/p-Si heterostructure. This structure can be a promising candidate for UV sensing applications owing to its high responsivity, sensitivity and easy fabrication process. (C) 2020 Elsevier B.V. All rights reserved.