TY - JOUR
T1 - Self-Passivation of 2D Ruddlesden-Popper Perovskite by Polytypic Surface PbI2 Encapsulation
AU - Jung, Hee Joon
AU - Stompus, Constantinos C.
AU - Kanatzidis, Mercouri G.
AU - Dravid, Vinayak P.
N1 - Funding Information:
This work made use of the EPIC facility of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205), the MRSEC program (NSF DMR-1720139) at the Materials Research Center, the International Institute for Nanotechnology (IIN), the Keck Foundation, and the State of Illinois, through the IIN. 2D HOIP synthesis and stability studies were supported by Office of Naval Research Grant (N00014-17-1-2231). This material is partially based on research sponsored by the Air Force Research laboratory under agreement number FA8650-15-2-5518. The U.S. Government is authorized to reproduce and distribute reprints for Governmental purposes notwithstanding any copyright notation thereon. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of Air Force Research Laboratory or the U.S. Government.
PY - 2019/9/11
Y1 - 2019/9/11
N2 - Two-dimensional Ruddlesden-Popper (2D RP) halide perovskites, C2MAn-1PbnI3n+1 (C = bulky ammonium cation; MA = methylammonium) with low n-members (n < 5), have been garnering sensational attention for photovoltaic and optoelectronic applications because of the long carrier diffusion lengths, long-term stability, and tunable bandgap. Yet, the surface modification of 2D RP under kinetic particle irradiation, such as light or electron irradiation, is ambiguous, even though it is imperative to elucidate long-stabilized conversion efficiency. Herein, we present molecular-scale observations of dynamic surface reconstruction of BA2MA2Pb3I10 (n = 3) 2D RP induced by the electron beam. The surface dynamics reveal lateral growth of polytypic PbI2 with 3R, 4H, and 2H structures at the edge and surface of the 2D perovskite, accompanied by simultaneous annihilation at the other edges. Local radiolysis occurs dominantly by the internal energy increase of electron momentum transfer, which triggers a sequential layer-by-layer degradation into PbI2. In situ observation of the polytypic PbI2 growth at the whole surface and edges of 2D RP under electron irradiation elucidates how the outer PbI2 self-passivation can protect inner 2D RP, causing longer operando stability.
AB - Two-dimensional Ruddlesden-Popper (2D RP) halide perovskites, C2MAn-1PbnI3n+1 (C = bulky ammonium cation; MA = methylammonium) with low n-members (n < 5), have been garnering sensational attention for photovoltaic and optoelectronic applications because of the long carrier diffusion lengths, long-term stability, and tunable bandgap. Yet, the surface modification of 2D RP under kinetic particle irradiation, such as light or electron irradiation, is ambiguous, even though it is imperative to elucidate long-stabilized conversion efficiency. Herein, we present molecular-scale observations of dynamic surface reconstruction of BA2MA2Pb3I10 (n = 3) 2D RP induced by the electron beam. The surface dynamics reveal lateral growth of polytypic PbI2 with 3R, 4H, and 2H structures at the edge and surface of the 2D perovskite, accompanied by simultaneous annihilation at the other edges. Local radiolysis occurs dominantly by the internal energy increase of electron momentum transfer, which triggers a sequential layer-by-layer degradation into PbI2. In situ observation of the polytypic PbI2 growth at the whole surface and edges of 2D RP under electron irradiation elucidates how the outer PbI2 self-passivation can protect inner 2D RP, causing longer operando stability.
KW - 2D Ruddlesden-Popper halide perovskite
KW - BAMAPbI 2D halide perovskite
KW - electron beam irradiation
KW - in situ TEM
KW - long-term stability
KW - polytypic PbI surface self-passivation
UR - http://www.scopus.com/inward/record.url?scp=85072133527&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85072133527&partnerID=8YFLogxK
U2 - 10.1021/acs.nanolett.9b02069
DO - 10.1021/acs.nanolett.9b02069
M3 - Article
C2 - 31424953
AN - SCOPUS:85072133527
VL - 19
SP - 6109
EP - 6117
JO - Nano Letters
JF - Nano Letters
SN - 1530-6984
IS - 9
ER -