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This paper presents the results of a combined experimental and analytical/computational study of the effects of pressure on photoconversion efficiencies of perovskite solar cells (PSCs). First, an analytical model is used to predict the effects of pressure on interfacial contact in the multilayered structures of PSCs. The PSCs are then fabricated before applying a range of pressures to the devices to improve their interfacial surface contacts. The results show that the photoconversion efficiencies of PSCs increase by ~40%, for applied pressures between 0 and ~7 MPa. However, the photoconversion efficiencies decrease with increasing pressure beyond ~7 MPa. The implications of the results are discussed for the fabrication of efficient PSCs.

In this study, we reported a low-temperature, one-step solution process to fabricate perovskite solar cells using dehydrated lead acetate as the lead source. These perovskite films were aged at 200 s before thermal annealing at 90 °C for 5 min. Uniform perovskite films with lesser pinholes were obtained by this technique. The inverted planar (n-i-p) perovskite solar cell device resulted in a power conversion efficiency of 13%. A substantial finding was that the devices demonstrated high reproducibility. We also investigated the effect of annealing temperature on the optical and structural properties of the films and on the photovoltaic performances of the fabricated solar cell devices. For the aforementioned, a low-temperature, one-step solution process, the optimal temperature was achieved at 90 °C.

Incorporation of cesium (Cs) into the perovskite layer has become a good strategy to boost the stability and power conversion efficiency (PCE) of perovskite solar cells (PSCs). However, a suitable and scalable method of Cs incorporation in a perovskite film that does not cause a significant increase in the optical bandgap is needed. In this paper, we introduce a thin layer of CsBr into a formamidinium (FA)-rich mixed halide perovskite film using the thermal evaporation technique. The effects of the thickness of the CsBr layer on the microstructural, structural, and optoelectronic properties and surface chemical states of the perovskite film are then studied. The results indicate that the CsBr layer thickness is able to tune the microstructural and optoelectronic properties of the perovskite film. Planar PSCs fabricated with different thicknesses of CsBr layers in the perovskite absorber exhibited different photovoltaic performance characteristics. The CsBr-modified PSC device with a 50 nm layer of CsBr in the perovskite layer showed a better PCE of 16.19% ± 0.17%, which was about 15% higher than that of the control device, and was able to retain nearly 70% of its initial PCE value after 120 days of storage in an unencapsulated state.

This paper presents the results of pressure-effects on performance characteristics of near-infra-red perovskite light emitting diodes (PeLEDs) using a combination of experimental and analytical/computational approaches. First, pressure-effects are studied using models that consider the deformation and contacts that occur around interfacial impurities and interlayer surface roughness in PeLEDs. The predictions from the model show that the sizes of the interfacial defects decrease with increasing applied pressure. The current–voltage characteristics of the fabricated devices are also presented. These show that the PeLEDs have reduced turn-on voltages (from 2.5 V to 1.5 V) with the application of pressure. The associated pressure-induced reductions in the defect density and the bandgaps of the perovskite layer are then used to explain the improved performance characteristics of the PeLED devices.