Mechanosynthesis of MAPbI3@Graphite Composites with Active Interfaces and Promising Photodetection Properties - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Chemistry of Materials Année : 2023

Mechanosynthesis of MAPbI3@Graphite Composites with Active Interfaces and Promising Photodetection Properties

Eric Gros-Daillon
  • Fonction : Auteur
Ferdinand Ledee
  • Fonction : Auteur

Résumé

Three-dimensional (3D) hybrid perovskites (HPs) are currently a key player in optoelectronic applications and, beyond the traditional photovoltaic applications, have also other great potentials as light-emitting diodes, lasers, photocatalysts, and photo- and X-ray detectors. However, despite the excellent performance of 3D HPs, certain HPs such as methylammonium lead iodide (CH3NH3PbI3 named MAPbI3) lack long-term environmental stability because they are very sensitive to humidity and degrade under oxygen and light exposures. Moreover, MAPbI3 films or single crystals or powders are mainly produced from precursor mixture methods and suffer some drawbacks such as the formation of intermediate phases with solvents affecting their performance. To face some of those problems, we have optimized the synthesis of MAPbI3 via a green solvent-free mechanosynthesis process, which also provides large amounts of powders, and to enhance its chemical stability, we have mixed MAPbI3 with graphite, which also granted the possibility to combine the different electronic properties of both components. The mechanosynthesis parameters have been optimized for both systems to minimize the defect amount, and their structural, optical, and electronic properties have been characterized. High-resolution transmission electron microscopy (HRTEM) and in situ HRTEM highlighted common crystallographic orientations between MAPbI3 nanograins (∼10 nm) in aggregates of mechanosynthesized (MS) powders. The band gap values and photoluminescence (PL) properties of mechanosynthesized MAPbI3 are in good agreement with the ones reported for MAPbI3 synthesized by chemical methods. A decrease in PL intensity related to the introduction of defects is observed with a longer grinding time, confirming that the selected grinding conditions were optimal. These mechanosynthesis conditions of MAPbI3 were found also suitable to obtain MAPbI3@Graphite composites with different amounts of graphite. A homogeneous distribution of few-layer graphite within the MAPbI3 matrix was noticed in powder-compacted wafers. Graphite-enhanced Raman scattering was observed with the composite with 5 wt % graphite showing its strong resistance to photodegradation and suggesting a charge transfer between graphite and MAPbI3. Such charge transfer is also in agreement with the quenching of the PL with an increasing amount of graphite. Further analysis of time-resolved PL decays confirmed, supported by X-ray detection results, that the presence of graphite impacted the charge transfer. The presence of graphite would induce a local modification of the Coulomb interaction, “attracting” the charge carriers at the graphite and MAPbI3 interfaces and thus favoring the charge separation and transport. In addition, the composite with 5 wt % graphite exhibited promising photodetection properties with a photoresponsivity of 1.5 × 103 A/W and an effective quantum effect of around 4.4 × 106 % at 400 nm with a light power of 330 nW. This high photoconductive gain matches with the trapping of one type of charge carrier, while the other one is multiplied via injection from the contact electrodes, thus contributing even more to the photoconductivity. These results highlighted that the mechanosynthesis, which is green and efficient in providing large amounts of powders, is suitable to design homogeneous MAPbI3@Graphite composites with strong interactions between graphite and MAPbI3 favoring an improved charge transfer and amplification of the photocurrent that will be very promising for photodetection applications.

Domaines

Matériaux
Fichier non déposé

Dates et versions

hal-04352008 , version 1 (18-12-2023)

Identifiants

Citer

Yihui Cai, Dominique Bégin, Charles Sidhoum, Adrien Girault, Thomas Fix, et al.. Mechanosynthesis of MAPbI3@Graphite Composites with Active Interfaces and Promising Photodetection Properties. Chemistry of Materials, 2023, 35 (23), pp.10188-10205. ⟨10.1021/acs.chemmater.3c02418⟩. ⟨hal-04352008⟩
21 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More