High‐Performance Perovskite Solar Cells with Large Grain‐Size obtained by using the Lewis Acid‐Base Adduct of Thiourea. Issue 6 (3rd April 2018)

• Record Type: Journal Article
• Authors: Wang, Shuo; Ma, Zirui; Liu, Beibei; Wu, Wenchao; Zhu, Yu; Ma, Ruixin; Wang, Chengyan
• Is Part Of: Solar RRL. Volume 2:Issue 6(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-04-03
• Subjects: intermediate phase -- perovskite solar cells -- large grains -- thiourea; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.201800034
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : Recently, perovskite solar cells (PSCs) have been rapidly developed, counting as the most promising alternative to the Si solar cells. The fabrication of perovskite films with controlled crystallinity and grain size is critical for highly efficient and stable solar cells. In this work, thiourea (TU) serving as a Lewis acid‐base adduct is introduced into the CH3 NH3 PbI3 precursor. A smooth and large grained perovskite crystal is obtained without the intermediate phase PbI2 · SC(NH2 )2 using the ideal thiourea amount. Thiourea, through forming MAI · PbI2 · DMSO · thiourea in perovskite precursor solution, significantly impacts the perovskite crystallinity and morphology, as proved using X‐ray diffraction patterns and infrared spectroscopy. Light harvesting, suppressed defect state, and enhanced charge separation and transport of the perovskite absorber layer are improved. The optimum performance of perovskite solar cells with TU demonstrated a power conversion efficiency (PCE) of 19.80%, an average steady‐state PCE of 18.60% and potent stability under ambient air. Abstract : The authors introduce different content of thiourea into MAPbI3 perovskite films and examine the impacts exerted by thiourea on the photovoltaic performance of perovskite solar cells. In addition, this work illustrates strategies for optimizing the thiourea content, enabling more light absorption and large grains. Thereby thiourea can be used to guide device architecture design and fabrication for high photovoltaic efficiency.