Ionic Additive Engineering Toward High‐Efficiency Perovskite Solar Cells with Reduced Grain Boundaries and Trap Density. (22nd June 2018)

• Record Type: Journal Article
• Authors: Cai, Feilong; Yan, Yu; Yao, Jiaxu; Wang, Pang; Wang, Hui; Gurney, Robert S.; Liu, Dan; Wang, Tao
• Is Part Of: Advanced functional materials. Volume 28:Number 34(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-06-22
• Subjects: additive engineering -- grain boundaries -- perovskite solar cells -- TACl -- trap density; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201801985
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Organic–inorganic hybrid perovskite solar cells have emerged as one of the promising photovoltaic candidates to generate renewable energy. However, the large amounts of grain boundaries and trap states that exist in the bulk or interfacial regions of perovskite films limit further enhancement of device efficiency. Herein, an additive engineering strategy is introduced employing trimethylammonium chloride in the methylammonium iodide precursor solution to prepare methylammonium lead iodide perovskite films with reduced grain boundaries and trap densities. This leads to an increased charge carrier diffusion coefficient and diffusion length, as evaluated by impedance and voltage decay measurements, intensity‐modulated photovoltage, and photocurrent spectroscopies. The proportion of nonradiative recombination processes is significantly reduced, consequently increasing device efficiency from 19.1% to 20.9% in these perovskite solar cells. Abstract : An ionic additive trimethylammonium chloride is introduced in the methylammonium iodide precursor solution to prepare methylammonium lead iodide perovskite films with reduced grain boundaries and trap densities, leading to reduced nonradiative recombination and increased carrier diffusion length, consequently increasing device efficiency from 19.1% to 20.9% in perovskite solar cells.