Journal
ADVANCED FUNCTIONAL MATERIALS
Volume 30, Issue 42, Pages -Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/adfm.202004312
Keywords
charge-carrier accumulation; perovskite; photoluminescence; trap states; trapping
Categories
Funding
- Engineering and Physical Sciences Research Council (EPSRC) UK
- European Commission
- EPSRC Centre for Doctoral Training in New and Sustainable Photovoltaics
- OxfordRadcliffe Scholarship
- EPSRC [EP/S004947/1, EP/P033229/1] Funding Source: UKRI
Ask authors/readers for more resources
Trap-related charge-carrier recombination fundamentally limits the performance of perovskite solar cells and other optoelectronic devices. While improved fabrication and passivation techniques have reduced trap densities, the properties of trap states and their impact on the charge-carrier dynamics in metal-halide perovskites are still under debate. Here, a unified model is presented of the radiative and nonradiative recombination channels in a mixed formamidinium-cesium lead iodide perovskite, including charge-carrier trapping, de-trapping and accumulation, as well as higher-order recombination mechanisms. A fast initial photoluminescence (PL) decay component observed after pulsed photogeneration is demonstrated to result from rapid localization of free charge carriers in unoccupied trap states, which may be followed by de-trapping, or nonradiative recombination with free carriers of opposite charge. Such initial decay components are shown to be highly sensitive to remnant charge carriers that accumulate in traps under pulsed-laser excitation, with partial trap occupation masking the trap density actually present in the material. Finally, such modelling reveals a change in trap density at the phase transition, and disentangles the radiative and nonradiative charge recombination channels present in FA(0.95)Cs(0.05)PbI(3,)accurately predicting the experimentally recorded PL efficiencies between 50 and 295 K, and demonstrating that bimolecular recombination is a fully radiative process.
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