Competence Center for Micro- and Nanotechnologies

Powered by the worldwide efforts of research groups experienced in dye-sensitized, and thin-film solar cells, perovskite solar cells (PSCs) reached apower conversion efficiency of 25.7% within 10 years. However, the presenceof defects and trap density within the active layer’s grain boundaries com-monly operates as non-radiative recombination centers. Hence, intensive effortshave been reported to passivate the inevitable bulk and interface defects of theactive layer using additives or post-treatment processing to enhance the effi-ciency and stability of PSCs. Herein, a facile post-treatment strategy based onwet processing methylammonium lead triiodide, MAPbI3(prepared from leadacetate and methylammonium iodide precursors) films with organic amine salts(FABr and FAI) is demonstrated. As a result, high-quality films of mixed per-ovskites (FAxMA1-xPbI3-xBrxand FAxMA1-xPbI3) were obtained. The surfacetreatment has efficiently passivate the defects in the host film, suppressingthe non-radiative carrier recombination. Compared to the control device, theincreased open-circuit voltage (from 0.5 V to 1 V) and fill factor (FF) values ofthe optimized device based on FAxMA1-xPbI3showed a PCE of 16.13%. And ourfindings revealed that post-treatment is possible on wet perovskite film agedfor a few minutes prior to its post-treatment, which saved the energy used forpre-annealing