Formation dynamics of CH3NH3PbI3 Perovskite following two-step layer deposition
Hybrid metal-halide perovskites have emerged as a leading class of semiconductors for optoelectronic devices because of their desirable material properties and versatile fabrication methods. However, little is known about the chemical transformations that occur in the initial stages of perovskite cr...
| Main Authors: | , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
American Chemical Society
2016
|
| _version_ | 1826270127303163904 |
|---|---|
| author | Patel, J Milot, R Wright, A Herz, L Johnston, M |
| author_facet | Patel, J Milot, R Wright, A Herz, L Johnston, M |
| author_sort | Patel, J |
| collection | OXFORD |
| description | Hybrid metal-halide perovskites have emerged as a leading class of semiconductors for optoelectronic devices because of their desirable material properties and versatile fabrication methods. However, little is known about the chemical transformations that occur in the initial stages of perovskite crystal formation. Here we follow the real-time formation dynamics of MAPbI3 from a bilayer of lead iodide (PbI2) and methylammonium iodide (MAI) deposited through a two-step thermal evaporation process. By lowering the substrate temperature during deposition, we are able to initially inhibit intermixing of the two layers. We subsequently use infrared and visible light transmission, X-ray diffraction, and photoluminescence lifetime measurements to reveal the room-temperature transformations that occur in vacuum and ambient air, as MAI diffuses into the PbI2 lattice to form MAPbI3. In vacuum, the transformation to MAPbI3 is incomplete as unreacted MAI is retained in the film. However, exposure to moist air allows for conversion of the unreacted MAI to MAPbI3, demonstrating that moisture is essential in making MAI more mobile and thus aiding perovskite crystallization. These dynamic processes are reflected in the observed charge-carrier lifetimes, which strongly fluctuate during periods of large ion migration but steadily increase with improving crystallinity. |
| first_indexed | 2024-03-06T21:35:59Z |
| format | Journal article |
| id | oxford-uuid:4648ce71-e41b-43e9-93d6-b9fbe8f72f52 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T21:35:59Z |
| publishDate | 2016 |
| publisher | American Chemical Society |
| record_format | dspace |
| spelling | oxford-uuid:4648ce71-e41b-43e9-93d6-b9fbe8f72f522022-03-26T15:12:50ZFormation dynamics of CH3NH3PbI3 Perovskite following two-step layer depositionJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4648ce71-e41b-43e9-93d6-b9fbe8f72f52EnglishSymplectic Elements at OxfordAmerican Chemical Society2016Patel, JMilot, RWright, AHerz, LJohnston, MHybrid metal-halide perovskites have emerged as a leading class of semiconductors for optoelectronic devices because of their desirable material properties and versatile fabrication methods. However, little is known about the chemical transformations that occur in the initial stages of perovskite crystal formation. Here we follow the real-time formation dynamics of MAPbI3 from a bilayer of lead iodide (PbI2) and methylammonium iodide (MAI) deposited through a two-step thermal evaporation process. By lowering the substrate temperature during deposition, we are able to initially inhibit intermixing of the two layers. We subsequently use infrared and visible light transmission, X-ray diffraction, and photoluminescence lifetime measurements to reveal the room-temperature transformations that occur in vacuum and ambient air, as MAI diffuses into the PbI2 lattice to form MAPbI3. In vacuum, the transformation to MAPbI3 is incomplete as unreacted MAI is retained in the film. However, exposure to moist air allows for conversion of the unreacted MAI to MAPbI3, demonstrating that moisture is essential in making MAI more mobile and thus aiding perovskite crystallization. These dynamic processes are reflected in the observed charge-carrier lifetimes, which strongly fluctuate during periods of large ion migration but steadily increase with improving crystallinity. |
| spellingShingle | Patel, J Milot, R Wright, A Herz, L Johnston, M Formation dynamics of CH3NH3PbI3 Perovskite following two-step layer deposition |
| title | Formation dynamics of CH3NH3PbI3 Perovskite following two-step layer deposition |
| title_full | Formation dynamics of CH3NH3PbI3 Perovskite following two-step layer deposition |
| title_fullStr | Formation dynamics of CH3NH3PbI3 Perovskite following two-step layer deposition |
| title_full_unstemmed | Formation dynamics of CH3NH3PbI3 Perovskite following two-step layer deposition |
| title_short | Formation dynamics of CH3NH3PbI3 Perovskite following two-step layer deposition |
| title_sort | formation dynamics of ch3nh3pbi3 perovskite following two step layer deposition |
| work_keys_str_mv | AT patelj formationdynamicsofch3nh3pbi3perovskitefollowingtwosteplayerdeposition AT milotr formationdynamicsofch3nh3pbi3perovskitefollowingtwosteplayerdeposition AT wrighta formationdynamicsofch3nh3pbi3perovskitefollowingtwosteplayerdeposition AT herzl formationdynamicsofch3nh3pbi3perovskitefollowingtwosteplayerdeposition AT johnstonm formationdynamicsofch3nh3pbi3perovskitefollowingtwosteplayerdeposition |