Journal
ADVANCED FUNCTIONAL MATERIALS
Volume 30, Issue 7, Pages -Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/adfm.201906763
Keywords
bulky cation additive; crystal growth; grain structure; perovskite solar cells; surface analysis
Categories
Funding
- Global Research Laboratory (GRL) Program through the National Research Foundation of Korea (NRF) - Ministry of Science and ICT [NRF-2017K1A1A2013153]
- EPSRC Plastic Electronics CDT [EP/L016702/1]
- UKRI Global Challenge Research Fund project SUNRISE [EP/P032591/1]
- Ramsay Memorial Trust
- EPSRC [EP/P032591/1] Funding Source: UKRI
Ask authors/readers for more resources
The origin of performance enhancements in p-i-n perovskite solar cells (PSCs) when incorporating low concentrations of the bulky cation 1-naphthylmethylamine (NMA) are discussed. A 0.25 vol % addition of NMA increases the open circuit voltage (V-oc) of methylammonium lead iodide (MAPbI(3)) PSCs from 1.06 to 1.16 V and their power conversion efficiency (PCE) from 18.7% to 20.1%. X-ray photoelectron spectroscopy and low energy ion scattering data show NMA is located at grain surfaces, not the bulk. Scanning electron microscopy shows combining NMA addition with solvent assisted annealing creates large grains that span the active layer. Steady state and transient photoluminescence data show NMA suppresses non-radiative recombination resulting from charge trapping, consistent with passivation of grain surfaces. Increasing the NMA concentration reduces device short-circuit current density and PCE, also suppressing photoluminescence quenching at charge transport layers. Both V-oc and PCE enhancements are observed when bulky cations (phenyl(ethyl/methyl)ammonium) are incorporated, but not smaller cations (Cs/MA)-indicating size is a key parameter. Finally, it demonstrates that NMA also enhances mixed iodide/bromide wide bandgap PSCs (V-oc of 1.22 V with a 1.68 eV bandgap). The results demonstrate a facile approach to maximizing V-oc and provide insights into morphological control and charge carrier dynamics induced by bulky cations in PSCs.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available