MRS Meetings and Events


EL04.05.04 2023 MRS Spring Meeting

Controlled Passivation by Lead Halides of Interfacial Defects of Perovskite Films for Emerging Electronic Applications

When and Where

Apr 13, 2023
9:30am - 9:45am

Moscone West, Level 3, Room 3004



Jihyun Kim1,William Jo1,Seho Yi1

Ewha Womans University1


Jihyun Kim1,William Jo1,Seho Yi1

Ewha Womans University1
In mixed organic–inorganic lead halide perovskites APbX<sub>3</sub> (A = methylammonium (MA) or formamidinium (FA); X is Cl, Br or I), the formation of secondary-phase excess lead iodide (PbI<sub>2</sub>) has some positive effects as a grain-boundary passivation on interstitial defects but can be detrimental to device stability and lead to large hysteresis effects in voltage sweeps. We converted PbI<sub>2</sub> into an inactive (NH<sub>4</sub><sup>+</sup>)-PbI<sub>2</sub> compound via pre-extracted NH<sub>4</sub>+/SnO<sub>2</sub> by NH<sub>4</sub>Cl passivator [1], which effectively stabilizes the perovskite crystalline phase. These effects were discussed with density functional theory (DFT) and shown to grain voltage sweep measurement by conductive atomic force microscopy (C-AFM) and surface photo-voltage by illuminated Kelvin probe force microscopy. We compared the current and voltage properties for insulating domains of PbI2, (Cl)-PbI<sub>2</sub>, and (NH<sub>4</sub><sup>+</sup>)-PbI<sub>2</sub> in-situ perovskite films. The ferro-electric properties were discovered on PbI<sub>2</sub> and (Cl)-PbI<sub>2</sub>, on the other hand (NH<sub>4</sub><sup>+</sup>)-PbI<sub>2</sub> show no ion migration. This means that inactive (NH<sub>4</sub><sup>+</sup>)-PbI<sub>2</sub> effects can be stabilized the indiscriminate ion movements on the perovskite-based optoelectronics. As a result, the perovskite solar cells (PSCs) achieve an average efficiency of 21.57 ± 0.45 % and best efficiency of 22.25 % [2] due to the dramatically enhanced open circuit voltage by 1.180 V, which is the main effect of efficiency improvement, and increase the operational device stability over 50 days in ambient conditions with ~50 % of relative humidity. It is very curious that the results also show passivated interface is an effective way to modify bifacial defects and electronic structures improving charge configuration with high resistant / low resistant states and its transfer and extraction, and eventually it is leading to new emergent electronic devices.<br/>[1] J. H. Kim, Y. S. Kim, H. R. Jung, and W. Jo, “Chlorine-passivation of the ozone-treated SnO<sub>2</sub> thin films: occurrence of oxygen vacancies for manipulation of conducting states and bipolarities in resistive switching”, Applied Surface Science 555, 149625 (2021).<br/>[2] J. H. Kim, J. H. Park, Y. H. Kim, and W. Jo, “Improvement of Open-Circuit Voltage Deficit via Pre-treated NH<sub>4</sub><sup>+</sup> Ion Modification of Interface between SnO<sub>2</sub> and Perovskite Solar cells”, Small, 2204173 (2022).


defects | diffusion

Symposium Organizers

Felix Deschler, University of Heidelberg
Linn Leppert, University of Twente
Sebastian Reyes-Lillo, Universidad Andres Bello
Carolin Sutter-Fella, Lawrence Berkeley National Laboratory

Publishing Alliance

MRS publishes with Springer Nature