Home > Cruise >

Solar RRL: highly crystalline and vertically oriented Dion Jacobson type quasi two dimensional perovskite controlled by solvent phase nucleation

wallpapers Cruise 2020-11-11

quasi two dimensional (q-2d) perovskite has better environmental stability thermal stability than the corresponding 3D perovskite which is one of the research hotspots in the field of perovskite solar cells. Dion Jacobson (DJ) type quasi two dimensional perovskite containing organic diamine cations can replace the van der Waals force between layers of ruddlesden Popper (RP) type q-2d perovskite by covalent bond in organic diamine cations which is expected to further improve the structural stability of materials. However the anisotropy of carrier transport in low dimensional materials makes the efficiency of q-2d perovskite devices very sensitive to their crystal orientation. In general the most thermodynamic rom crystal orientation is not conducive to the collection of photogenerated carriers in q-2d perovskite system which makes it difficult to be accepted. Therefore it is necessary to deeply underst the crystallization process of q-2d perovskite find a mechanism to induce the vertical preferred orientation of q-2d perovskite.

in view of this Yuan Yongbo research group of School of physics electronics of Central South University further studied the nucleation grain orientation morphology evolution of DJ type q-2d perovskite on the basis of previous research on RP type q-2d perovskite concluded that the three key stages of the nucleation growth process of DJ perovskite are the formation of PbI2 solvent phase (PDS) the formation of quasi-3D by PDS reaction Perovskite (stage II) quasi 3D perovskite were used as templates to induce the oriented growth of quasi 2D perovskite on its surface (stage III). The PDS formed in stage I plays an important role in regulating the nucleation growth of q-2d perovskite crystal in stage III which is an important factor to determine the morphology of DJ perovskite films. In the process of solvent volatilization the heterogeneous nucleation of PDS at the solution air interface is conducive to the formation of surface (quasi 3D perovskite) template which induces the top-down directional growth of q-2d perovskite grains forming a crystal orientation with high conductivity plane perpendicular to the substrate; however excessive homogeneous nucleation of PDS in the solution will lead to disordered orientation growth of q-2d perovskite grains form competitive growth pattern. The results show that the addition of proper amount of additives in the precursor solution can effectively inhibit the formation of high-quality PbI2 films. The results show that the energy conversion efficiency of PXD based DJ perovskite solar cells increases from 1.2% to 15.6%. The crystallization control strategy has been proved to be suitable for a variety of DJ perovskite materials based on different organic diamine spacer layers (p-phenylenediamine (PPD) p-xylylene diamine (PXD) propane-13-diammonium (PDA)).

in addition by testing the variable temperature conductivity of PPD based PXD based DJ type quasi two-dimensional perovskites the research group found that even if the organic interlayer spacing was shorter than that of RP perovskite (PPD based: 4.56 Å; PXD based: 6.74 Å; BA based RP perovskite: 7.15 Å) the ionon migration in the materials could still be effectively inhibited below 335 K. At the same time the optimized PXD based perovskite cells show significantly improved film device stability the unpacked devices can still maintain more than 90% of the initial efficiency under load mode continuous illumination for 700 hours. This study provides a way to control the crystallization process of q-2d perovskite materials also provides a reference for the design of perovskite devices with low ion migration trend high stability. The results of

were recently published in solar RRL (DOI: 10.1002 / Solr. 202000371). Wang Jifei a doctoral cidate from Central South University is the first author while Lin Yun Ding Liming Yuan Yongbo are the corresponding authors.

MIS-ASIA is an online content marketing platform that has a large number of visitors worldwide. It is considered to be the leading IT, mechanical, chemical, and nanomaterial information distributor in the Asia-Pacific region. The MIS-ASIA website provides high-quality articles and news on digital information technology, mechanical technology, nanotechnology, biology and science for scientists, engineers and industry experts, machinery suppliers and buyers, chemical suppliers and laboratories. If you need advertising and posting service, or you need to start sponsorship, please contact us.