| Autor: |
Fassl, Paul, Lami, Vincent, Berger, Felix J., Falk, Lukas M., Zaumseil, Jana, Richards, Bryce S., Howard, Ian A., Vaynzof, Yana, Paetzold, Ulrich W. |
| Rok vydání: |
2020 |
| Předmět: |
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| Zdroj: |
Matter 4 (2021) 1391-1412 |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1016/j.matt.2021.01.019 |
| Popis: |
The internal luminescence quantum efficiency ($Q_\mathrm{i}^\mathrm{lum}$) provides an excellent assessment of the optoelectronic quality of semiconductors. To determine $Q_\mathrm{i}^\mathrm{lum}$ of perovskite films from the experimentally accessible external luminescence quantum efficiency ($Q_\mathrm{e}^\mathrm{lum}$) it is essential to account for photon recycling, and this requires knowledge of the photon escape probability ($p_\mathrm{e}$). Here, we establish an analysis procedure based on a curve fitting model that accurately determines $p_\mathrm{e}$ of perovskite films from photoluminescence (PL) spectra measured with a confocal microscope and an integrating sphere setup. We show that scattering-induced outcoupling of initially-trapped PL explains commonly observed red-shifted and broadened PL spectral shapes and leads to $p_\mathrm{e}$ being more than 10% higher in absolute terms compared to earlier assumptions. Applying our model to CH$_3$NH$_3$PbI$_3$ films with exceptionally high $Q_\mathrm{e}^\mathrm{lum}$ up to 47.4% sets a real benchmark for $Q_\mathrm{i}^\mathrm{lum}$ at $78.0 \pm 0.5\%$, revealing there is beyond a factor of two more scope for reducing non-radiative recombination than previously thought. |
| Databáze: |
arXiv |
| Externí odkaz: |
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