Enhanced Photoresponsivity of Perovskite QDs/Graphene Hybrid Gate‐Free Photodetector by Morphologically Controlled Plasmonic Au Nanocrystals

• Published in: Advanced optical materials 2023-08, Vol.11 (15), p.n/a
• Main Authors: Yadav, Shyam Narayan Singh, Hanmandlu, Chintam, Patel, Dinesh Kumar, Singh, Rajan Kumar, Chen, Chun‐Yen, Wang, Yen‐Yu, Chu, Chih‐Wei, Liang, Chi‐Te, Lin, Chih‐Ting, Lu, Yu‐Jung, Yen, Ta‐Jen
• Format: Article
• Language: English
• Subjects: Absorptivity; Carrier density; Carrier mobility; Current carriers; Gold; Graphene; hybrid photodetectors; light–matter interaction; MAPbBr3 perovskite quantum dots; Materials science; Nanocrystals; Optics; Optoelectronics; Perovskites; Photometers; plasmonic gold nanocrystals; Plasmonics; Quantum dots; Quantum efficiency
• ISSN: 2195-1071; 2195-1071
• DOI: 10.1002/adom.202300131

Owing to their excellent carrier mobility, high absorption coefficient, exceptional quantum efficiency, and low‐cost solution processability, perovskite quantum dots (PQDs) are a promising candidate for photodetection. However, PQDs‐based photodetectors typically show poor optoelectronic performances, mainly limited by their weak light–matter interaction. In this work, MAPbBr3 PQDs are hybridized with graphene (Gr) and morphologically controlled plasmonic gold nanocrystals (AuNCs) to demonstrate a superior photodetector at 432 nm through a synergetic effect. The experimental results indicate that three shaped AuNCs (i.e., sphere, the octahedron (OD), and rhombic dodecahedron (RD)) all contribute to better photodetection behaviors due to surface trap state passivation and enhanced charge carrier densities with longer lifetime compared to that of pristine PQDs. In particular, the PQDs/RD‐AuNCs/Gr system demonstrates a record‐high responsivity of 2.7 × 105 A W−1, a detectivity of 4.9 × 1013 Jones, and external quantum efficiency (EQE) of 7.9 × 107% at 1.6 µW cm−2 illumination power density of 432 nm wavelength with a lowest applied voltage of 1.0 V for a gate‐free PQDs/AuNCs/Gr‐based photodetector. Furthermore, to the authors’ knowledge, this device shows the highest responsivity among the PQDs/AuNCs/Gr‐based electrostatic gate‐free lateral configuration photodetectors. To take advantage of the synergistic effects of the three materials, Perovskite QDs/Graphene hybrid gate‐free photodetector has been developed. Incorporating shaped gold nanocrystals in Perovskite QDs/Graphene enhanced optical characteristics by intensifying the light–matter interaction and delaying carrier decay by passivating the trap state. As a result, the demonstrated photodetector outperformed the lateral photodetector and achieved the highest optoelectronic performance.