Single‐step post‐production treatment of lead acetate precursor‐based perovskite using alkylamine salts for reduced grain‐boundary related film defects. Issue 11 (4th August 2022)

• Record Type: Journal Article
• Authors: Gebremichael, Zekarias Teklu; Alam, Shahidul; Stumpf, Steffi; Diegel, Marco; Schubert, Ulrich S.; Hoppe, Harald
• Is Part Of: Nano select. Volume 3:Issue 11(2022)
• Page Start: 1491
• Page End: 1501
• Publication Date: 2022-08-04
• Subjects: alkyl amine salts -- inverted perovskite solar cells -- perovskite film crystallinity -- post‐treatment passivation -- power conversion efficiency -- Wet MAPbI3 film; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.5
• DOI: 10.1002/nano.202200006
• Languages: English
• ISSNs: 2688-4011

Abstract

Abstract: Powered by the worldwide efforts of research groups experienced in dye‐sensitized, and thin‐film solar cells, perovskite solar cells (PSCs) reached a power conversion efficiency of 25.7% within 10 years. However, the presence of defects and trap density within the active layer's grain boundaries commonly operates as non‐radiative recombination centers. Hence, intensive efforts have been reported to passivate the inevitable bulk and interface defects of the active layer using additives or post‐treatment processing to enhance the efficiency and stability of PSCs. Herein, a facile post‐treatment strategy based on wet processing methylammonium lead triiodide, MAPbI3 (prepared from lead acetate and methylammonium iodide precursors) films with organic amine salts (FABr and FAI) is demonstrated. As a result, high‐quality films of mixed perovskites (FAx MA1‐x PbI3‐x Brx and FAx MA1‐x PbI3 ) were obtained. The surface treatment has efficiently passivate the defects in the host film, suppressing the non‐radiative carrier recombination. Compared to the control device, the increased open‐circuit voltage (from 0.5 V to 1 V) and fill factor (FF) values of the optimized device based on FAx MA1‐x PbI3 showed a PCE of 16.13%. And our findings revealed that post‐treatment is possible on wet perovskite film aged for a few minutes prior to its post‐treatment, which saved the energy used for pre‐annealing. Abstract : Post‐treatment has been carried out on wet host film of (MAPbI3 ) aged for 3 minutes prior to its treatment. The host film, with evident pinholes was changed into smooth morphology and larger grain‐size mixed FAx M1‐x PbI3‐x Brx and FAx MA1‐x PbI3 films upon post‐treatment using FABr and FAI solutions respectively. Compared to the control device, the post‐treated devices had higher fill factor (FF) and a double rise in Open‐circuit voltage (VOC ), leading to enhanced device efficiency. Our findings has also proved that post‐treatment is possible on wet films that saved the energy for pre‐annealing during post‐treatment.