Category: Publications

Organic A’-site ligand structure plays a crucial role in the crystal growth of 2D perovskites, but the underlying mechanism has not been adequately understood. This problem is tackled by studying the influence of two isomeric A’-site ligands, linear-shaped n-butylammonium (n-BA+) and branched iso-butylammonium (iso-BA+) on 2D perovskites from precursor to device, with a combination of in situ grazing-incidence wide-angle X-ray scattering and density functional theory.… Read More

The growth of high-quality tin-based perovskite films remains a grand challenge due to the uncontrollable crystallization kinetics. Here, we report a facile strategy to realize an epitaxial-like growth of highly oriented tin-based perovskite films with the assistance of perovskite quantum dots (PQDs). Synchrotron-based in situ X-ray scattering results reveal that PQDs can act as nucleation centers to promote the growth of highly oriented perovskite crystals for both FASnI₃ and MASnI₃ systems.… Read More

Designing new high-performance non-fullerene acceptors is the key driving force for the development of organic solar cells (OSCs). In this work, a new acceptor, BOEH‑4Cl, was designed based on the end-group chlorination of L8-BO. Theoretical calculations successfully predicted the expected experimental results based on the optoelectronic properties of BOEH-4Cl and L8-BO and intermolecular interaction of PM6/BOEH-4Cl or L8-BO.… Read More

The tuning of vertical morphology is critical and challenging for organic solar cells (OSCs). In this work, a high open-circuit voltage (VOC) binary D18-Cl/L8-BO system is attained while maintaining the high short-circuit current (JSC) and fill factor (FF) by employing 1,4-diiodobenzene (DIB), a volatile solid additive. It is suggested that DIB can act as a linker between donor or/and acceptor molecules, which significantly modifies the active layer morphology.… Read More

Cesium lead based all-inorganic perovskite solar cells (PSCs) are promising candidates for tandem solar cells owing to their favorable thermal stability and suitable bandgap. However, to exploit the advantage to the full, there is still huge room to reduce energy loss and enhance the V_OC. In this work, low-temperature processed ZnO was developed as an ETL alternative.… Read More

The record power conversion efficiency of organic photovoltaic (OPV) has been boosting rapidly with the development of novel materials and morphology optimization of bulk heterojunction (BHJ) active layer. However, the quantitative determination of out-of-plane nanoscale phase structure of BHJ is still under great challenge. The thin film device structure breaks the symmetry into the in-plane (IP) direction and out-of-plane (OOP) direction with respect to the substrate, leading to an intrinsic anisotropy in the bulk morphology.… Read More

Metal halide perovskites are of fundamental interest in the research of modern thin-film optoelectronic devices, owing to their widely tunable optoelectronic properties and solution processibility. To obtain high-quality perovskite films and ultimately high-performance perovskite devices, it is crucial to understand the film formation mechanisms, which, however, remains a grand challenge, due to the complexity of perovskite composition, dimensionality, and processing conditions.… Read More

Light soaking (LS) has been reported to positively influence the device performance of perovskite solar cells (PSCs), which, however, could be potentially harmful to the loaded devices due to the unstable output. There are very few reports on controls over the LS effect, especially in all-inorganic PSCs. In this work, we present a remarkable LS induced performance enhancement of CsPb(I1-xBrx)3 based PSCs.… Read More

The bulk-heterojunction morphology of organic solar cells is well recognized to be critical to the device performance and has received extensive research efforts in developing viable morphology tuning strategies. In this work, we present a morphology tuning approach for the molecular packing orientation, that is, through the ternary mixing of a donor polymer FTAZ with two distinctly oriented non-fullerene acceptors, IDIC and INIC3.… Read More

Two-step fabricated FAPbI₃-based perovskites have attracted increasing attention because of their excellent film quality and reproducibility. However, the underlying film formation mechanism remains mysterious. In this work, the crystallization kinetics of a benchmark FAPbI₃-based perovskite film with sequential A-site doping of Cs⁺ and GA⁺ has been revealed by in situ X-ray scattering and first-principles calculations.… Read More