Publications by authors named "Florent Sahli"

Silicon solar cells are approaching their theoretical efficiency limit of 29%. This limitation can be exceeded with advanced device architectures, where two or more solar cells are stacked to improve the harvesting of solar energy. In this work, we devise a tandem device with a perovskite layer conformally coated on a silicon bottom cell featuring micrometric pyramids-the industry standard-to improve its photocurrent.

View Article and Find Full Text PDF

The development of stable materials, processable on a large area, is a prerequisite for perovskite industrialization. Beyond the perovskite absorber itself, this should also guide the development of all other layers in the solar cell. In this regard, the use of NiO as a hole transport material (HTM) offers several advantages, as it can be deposited with high throughput on large areas and on flat or textured surfaces via sputtering, a well-established industrial method.

View Article and Find Full Text PDF

Halide perovskite/crystalline silicon (c-Si) tandem solar cells promise power conversion efficiencies beyond the limits of single-junction cells. However, the local light-matter interactions of the perovskite material embedded in this pyramidal multijunction configuration, and the effect on device performance, are not well understood. Here, we characterize the microscale optoelectronic properties of the perovskite semiconductor deposited on different c-Si texturing schemes.

View Article and Find Full Text PDF

The remarkable recent progress in perovskite photovoltaics affords a novel opportunity to advance the power conversion efficiency of market-dominating crystalline silicon (c-Si) solar cells. A severe limiting factor in the development of perovskite/c-Si tandems to date has been their inferior light-harvesting ability compared to single-junction c-Si solar cells, but recent innovations have made impressive headway on this front. Here, we provide a quantitative perspective on future steps to advance perovskite/c-Si tandem photovoltaics from a light-management point of view, addressing key challenges and available strategies relevant to both the 2-terminal and 4-terminal perovskite/c-Si tandem architectures.

View Article and Find Full Text PDF

Tandem devices combining perovskite and silicon solar cells are promising candidates to achieve power conversion efficiencies above 30% at reasonable costs. State-of-the-art monolithic two-terminal perovskite/silicon tandem devices have so far featured silicon bottom cells that are polished on their front side to be compatible with the perovskite fabrication process. This concession leads to higher potential production costs, higher reflection losses and non-ideal light trapping.

View Article and Find Full Text PDF

Perovskite/silicon tandem solar cells with high power conversion efficiencies have the potential to become a commercially viable photovoltaic option in the near future. However, device design and optimization is challenging because conventional characterization methods do not give clear feedback on the localized chemical and physical factors that limit performance within individual subcells, especially when stability and degradation is a concern. In this study, we use light beam induced current (LBIC) to probe photocurrent collection nonuniformities in the individual subcells of perovskite/silicon tandems.

View Article and Find Full Text PDF