Quasi-2D perovskite@graphene hybrid for high performance and stable photodetection

Sapthami Hegde^1*, Surojit Chattopadhyay¹

¹Institute of Biophotonics, National Yang-Ming Chiao-Tung University, Beitou, Taipei, Taiwan

* Presenter:Sapthami Hegde, email:sapthami.hegde.7@gmail.com

Organometal halide perovskites, like FAPbI₃, are new-age materials with remarkable and adaptive optoelectronic properties best suited for photodetection application. However, FAPbI3 in its 3D structure is prone to environmental degradation, hindering its application. Incorporation of bulky organic cations in their structure revamps the 3D perovskites into quasi-2D perovskites, rendering them robust against degradation. We have synthesized DJ phase perovskites [DAO(FA)_n-1Pb_nI_3n+1] of various ‘n’ with incorporation of diamino-octane (DAO) cation in FAPbI3. With aid of various studies including synchrotron based X-ray characterization, we show improved crystallinity and stability of the quasi-2D perovskite film. We have fabricated perovskite@graphene photodetector (PD) devices with 3D, 2D and quasi-2D perovskite films. The 3D perovskite@graphene device exhibited an unstable, and a weak photoresponse. However, with quasi-2D perovskite films, photoresponsivity and detectivity to ~ 10⁷ AW^-1, and ~10¹⁶ Jones, respectively, upon illumination of 42.25 nW/cm² of 405 nm laser, under 1 V bias was achieved. This result paves way to stabilize the perovskites and study its role in high performance optoelectronic devices.

Keywords: Quasi-2D Perovskites, High performance Photodetector, Graphene, Synchrotron characterization