The Role of Diammonium Cation on the Structural and Optoelectronic Properties in 3D Cesium-Formamidinium Mixed-Cation Perovskite Solar Cells

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

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Detail(s)

Original languageEnglish
Article number1900140
Journal / PublicationSolar RRL
Volume3
Issue number8
Online published15 May 2019
Publication statusPublished - Aug 2019

Abstract

Incorporating diammonium cations, which electrostatically connect the adjacent inorganic slabs ([PbI6]4−), into 3D perovskite is recently proposed to develop high‐performance perovskite solar cells (PSCs). However, due to limited studies, the effects of these organic cations on the perovskite structural and optoelectronic properties are yet to be understood. Herein, a diammonium cation, propane‐1,3‐diammonium (PDA), is first proposed to modulate the cesium–formamidinium (Cs–FA)‐mixed cation perovskite. By increasing the PDA content, the efficiency of the Cs0.15FA0.85 − xPDAxPbI3 PSC first increases and then drastically decreases. The highest power conversion efficiency (PCE) of 18.10% obtained by Cs0.15FA0.83PDA0.02PbI3 is superior to that of the Cs0.15FA0.85PbI3 (16.82%). Through systematic investigations, it is revealed that the PDA content–dependent efficiency is attributed to a competition between the enhanced defect passivation and emerged excitonic effect with an increased PDA content. Moreover, the encapsulated Cs0.15FA0.83PDA0.02PbI3 device exhibits almost 1.5 times increased stability than the Cs0.15FA0.85PbI3 counterpart, with 83% of its initial efficiency retained after 500 h exposure, under continuous light soaking at 60 °C in ambient air. This study provides a practical strategy to enhance the device stability without sacrificing the efficiency and deepens our understanding on effects of diammonium cation incorporated in 3D perovskite.

Research Area(s)

  • defect passivation, diammonium cations, excitonic effect, inverted planar perovskite solar cells, METHYLAMMONIUM LEAD IODIDE, CHARGE-CARRIER DYNAMICS, HYBRID PEROVSKITES, HALIDE PEROVSKITES, ION MIGRATION, EFFICIENCY, HYSTERESIS, HEAT, PASSIVATION, STABILITY

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