nanoGUNE Colloquium: Manipulation of Low Dimensional Hybrid Perovskites: breaking efficiency and stability limits of wide band gap perovskite solar cells

Halide perovskites are dominating the field of next generation solar cells. Beyond traditional “3D” perovskites, low dimensional perovskites (LDPs) – intended to be single/few inorganic layers (typically <3) spaced by large organic cations – have recently attracted wide interest for their added their higher structural stability. Used as interfacial layers on top of 3D perovskites, they empowered perovskite solar cell stability1. Besides that, LDPs have not found an application yet mainly due to their wider band gap and disordered morphology which negatively impact charge transport (happening along the inorganic backbone). Lack of knowledge on how to manipulate the orientation of the inorganic sheets is the actual bottleneck. This limits vertical charge percolation and efficiency, ultimately making them uncompetitive in the solar cells arena.

Here, I will present the main applications of LDP in highly efficient solar cells, and I will present a new interfacial design using ferroelectric LDP as a mean to boost charge extraction2. Beyond their role as interfacial layers, I will also discuss a novel effective strategy to implement LDP as active layer for wide band gap solar cells. We uplifted the charge transport barrier being able of inducing a vertical growth of the inorganic framework. As a result, we break LDPs efficiency limits, triggering verticalcharge percolation, allowing us reaching a “record” efficiency of 9.4 % with a device Voc of 1.4 eV, the highest so far for LDPs solar cells. Such proof of concept intimately demonstrates the potential of controlling the crystalline orientation of LDPs providing an essential strategy for boosting their performances3, 4. The results pave the way for their implications into emerging field, from indoor PV for IoT powering, to building integration or agrivoltaics.

References:

1. Teale S., Grancini G.* Nature Energy 9, 779–792 (2024)

2. Pica G., Grancini G. * Nature Comm, in press

3. A. Zanetta & G. Grancini, Patent n. 102022000025854 (December 2022), Title "Process for inducing crystal orientation in low dimensional perovskites".

4. Zanetta A., Grancini G. * Nature Comm, Just Accepted