All-Nanoparticle SnO₂/TiO₂ Electron-Transporting Layers Processed at Low Temperature for Efficient Thin-Film Perovskite Solar Cells

Abstract

Solution processed metal halide perovskite materials have revealed outstanding optoelectronic features that make them uniquely suited for photovoltaic applications. Although a rapid progress has led to performances similar to inorganic thin film technologies, the fabrication method of some of the most widely used electron selective layers, based on either mesoporous architectures or high annealing temperatures, may limit yet a future large scale production. In that regard, planar perovskite solar cell configurations that can be processed at low temperatures are more desirable. Herein, we demonstrate that a few tens of nanometers thick bilayer, made of two types of inorganic oxide nanoparticles, can perform as a robust and low temperature processed electron selective contact for planar perovskite solar cells. Aside from boosting the average efficiency of planar opaque devices, the proposed method allowed us to preserve the main photovoltaic characteristics when thinner active layers, usually exhibiting a non-continuous morphology, were integrated for semi-transparent cells. By providing excellent electronic and coverage features against the bottom electrode, this novel configuration may hence offer an alternative route to approach future inexpensive printable methodologies for the fabrication of efficient low temperature perovskite solar cells.

Relation between Fluorescence Quantum Yield and Open‐Circuit Voltage in Complete Perovskite Solar Cells

“…This can easily be seen from Equation , in which the A ( E , θ ) terms in the numerator and denominator would rub out, leaving a V oc,rad expression depending only on the thickness‐independent S ( E ) and B ( E ). The decrease in V oc,rad with the perovskite thickness can be qualitatively attributed to an increased optical absorption mostly in the bandgap region, which implies a decrease in the perovskite effective optical bandgap . In addition to this decreasing trend, one observes an oscillatory pattern that likely results from optical interference.…”

“…The decrease in V oc,rad with the perovskite thickness can be qualitatively attributed to an increased optical absorption mostly in the bandgap region, which implies a decrease in the perovskite effective optical bandgap. [1,4,27] In addition to this decreasing trend, one observes an oscillatory pattern that likely results from optical interference. This clearly demonstrates the importance of performing calculations taking into account coherent effects, angle dependence, and a realistic solar cell structure with realistic layer thicknesses and energy-dependent dielectric functions.…”

Predictions and Strategies Learned from Machine Learning to Develop High‐Performing Perovskite Solar Cells

“…The performances of different ML algorithms for the prediction of the PCE of PSCs are shown in Table 1. Due to the complexity of the reported experimental values (for example, in our dataset, for solar cells with E g = 1.5 eV, ΔH = 0.15 eV, and ΔL = 0.2 eV, PCE could either be 20.5% [35] or 15.2% [36] ), all the RMSE values were not very small. But among all the algorithms, the ANN and RF behaved the best for both true bandgap and predicted bandgap due to their smallest RMSE values.…”

Doping in Semiconductor Oxides‐Based Electron Transport Materials for Perovskite Solar Cells Application

“…It was found that the heterojunction SnO 2 /TiO 2 gradient as a driving force could promote the charge transport from the perovskite photoactive layer into the ETL. However, Martinez‐Denegri et al [ 240 ] fabricated several tens of nanometer‐thick bilayers SnO 2 /TiO 2 as an ETL and applied it into translucent PSCs. The higher coverage of the ITO substrates would improve the average efficiency of planar structure translucent devices.…”