Spectroscopic ellipsometry and solar cell performance of Cs-doped MA0.05FA0.95Pb(I0.98Br0.02)3 triple cation perovskite thin films for solar cell applications

Modeling the performance of perovskite solar cells with inserting porous insulating alumina nanoplates

“…S1(a)]; (ii) defining the absorption coefficients of FA 0.95 MA 0.05 Pb(I 0.98 Br 0.02 ) 3 using α(λ ) = 4πκ(λ )/λ , where κ(λ ) is obtained from Ref. [4] and is the imaginary part of the refractive index [see Fig. S1(b)]; and (iii) defining photon generation rate as ϕ(λ ) = λ /hc × F(λ ), with F(λ ) representing the intensity of AM 1.5 G spectrum [see Fig.…”

Thermal Performance of Perovskite‐Based Photovoltaics for Operation in Low Earth Orbit

“…The onset of spectral oscillatory features below 1.6 eV is consistent with a predicted bandgap energy of 1.6 eV from Tauc plotting of the extinction and is consistent with similar materials in the literature. [20,23] The plot of the refractive index and extinction coefficient is shown in Figure 3a. As can be seen, the perovskite experiences high levels of absorption within its region of quantum efficiency from 300 to 800 nm.…”

“…The oscillator fitting approach was adopted both to ensure consistency with the Kramers–Kronig relations, which are not necessarily maintained in the direct fitting, and to decrease noise in the optical constant fits. Following the approach in El‐Naggar et al, [ 20 ] the oscillator model was composed of a combination of Herzinger–Johs parameterized semiconductor , Tauc–Lorentz, and Gaussian oscillators. The oscillator is a flexible function designed to parameterize both the fundamental direct bandgap and higher order interband transitions in typical direct bandgap semiconductor materials.…”

“…[ 22 ] Additionally, three Gaussian oscillators were employed to parametrize salient features in the ellipsometry spectra which could potentially be attributed to Cs‐donor localized states near the conduction band minimum. [ 20 ] The optical model consisted of a semi‐infinite silicon substrate, 2 nm of native oxide, 520 nm of absorber film, and 8 nm surface roughness (50% fill fraction) with ambient air. Fitting of the oscillator model parameters was performed with the Levenberg–Marquardt nonlinear least squares algorithm to minimize the mean squared error in the spectral and angular ellipsometry measurements.…”

“…The onset of spectral oscillatory features below 1.6 eV is consistent with a predicted bandgap energy of 1.6 eV from Tauc plotting of the extinction and is consistent with similar materials in the literature. [ 20,23 ]…”