Category: Publications

Heterovalent doping of halide perovskite nanocrystals (NCs), offering potential tunability in optical and electrical properties, remains a grand challenge. Here, we report for the first time a controlled doping of monovalent Ag⁺ into CsPbBr₃ NCs via a facile room temperature synthesis method. Our results suggest that Ag⁺ ions act as substitutional dopants to replace Pb²⁺ ions in the perovskite NCs, shifting the Fermi level down-towards the valence band and in turn inducing a heavy p-type character.… Read More

Fused-ring electron acceptors (FREAs), as a family of non-fullerene acceptors, have achieved tremendous success in pushing the power conversion efficiency of organic solar cells. Here, we reported the detailed molecular packing motifs of two extensively studied FREAs – ITIC and ITIC-Th, which is revealed for the first time the long-range structure ordering along the backbone direction originated from favored end group π-π stacking.… Read More

The stability of perovskite solar cells (PSCs) has been greatly improved recently while very few studies focus on the long-term stability of the perovskite precursor solution. We report a novel route to greatly enhance the long-term stability of perovskite precursor solutions by incorporating a non-fullerene small molecule ITIC-Th. We found that the incorporation of ITIC-Th in the perovskite precursor solution can effectively suppress the unwanted yellow non-perovskite phase (δ-phase) commonly formed in the FAPbI₃-based perovskite film made from a long-time aged precursor solution and consequently promote the formation of photoactive perovskite phase (α-phase).… Read More

Following our previously proposed selection rule for the two polymers capable of comparable loadings, we report in this work a ternary system composed of two morphologically compatible polymers with distinct chemical structures that can achieve a high PCE of 9.0% with a mass ratio of 1 : 1. Besides the expected improvement in short circuit current due to the broadening of the absorption spectrum, the fill factor of the ternary device is improved significantly.… Read More

Ternary organic solar cells are emerging as a promising strategy to enhance device power conversion efficiency by broadening the range of light absorption via the incorporation of additional light-absorbing components. However, how to find compatible materials that allow comparable loadings of each component remains a challenge. In this article, we focus on studying the donor polymer compatibilities in ternary systems from a morphological point of view.… Read More