TY  - JOUR
AU  - Ochoa-Martinez, Efrain
AU  - Ochoa, Mario
AU  - Ortuso, Roberto D.
AU  - Ferdowsi, Parnian
AU  - Carron, Romain
AU  - Tiwari, Ayodhya N.
AU  - Steiner, Ullrich
AU  - Saliba, Michael
TI  - Physical Passivation of Grain Boundaries and Defects in Perovskite Solar Cells by an Isolating Thin Polymer
JO  - ACS energy letters
VL  - 6
IS  - 7
SN  - 2380-8195
CY  - Washington, DC
PB  - American Chemical Society
M1  - FZJ-2021-05679
SP  - 2626 - 2634
PY  - 2021
AB  - Passivation and interlayer engineering are important approaches to increase the efficiency and stability of perovskite solar cells. Thin insulating dielectric films at the interface between the perovskite and the charge carrier transport layers have been suggested to passivate surface defects. Here, we analyze the effect of depositing poly(methyl methacrylate) (PMMA) from a very low-concentration solution. Spatial- and time-resolved photoluminescence and atomic force microscopy analyses of samples with diverse morphologies demonstrate the preferential deposition of PMMA in topographic depressions of the perovskite layer, such as grain and domain boundaries. This treatment results in an increase in the fill factor of more than 4% and an absolute efficiency boost exceeding 1%, with a maximum efficiency of 20.4%. Based on these results, we propose a physical isolation mechanism rather than a chemical passivation of perovskite defects, which explains not only the data of this study but also most results found in earlier works.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000672746800032
DO  - DOI:10.1021/acsenergylett.1c01187
UR  - https://juser.fz-juelich.de/record/904109
ER  -