Direct Observation on p- to n-Type Transformation of Perovskite Surface Region during Defect Passivation Driving High Photovoltaic EfficiencyShow others and affiliations
2021 (English)In: Joule, E-ISSN 2542-4351, Vol. 5, no 2, p. 467-480Article in journal (Refereed) Published
Abstract [en]
Perovskite solar cells (PSCs) suffer from significant nonradiative recombination, limiting their power conversion efficiencies. Here, for the first time, we directly observe a complete transformation of perovskite MAPbI(3) surface region energetics from p- to n-type during defect passivation caused by natural additive capsaicin, attributed to the spontaneous formation of a p-n homojunction in perovskite active layer. We demonstrate that the p-n homojunction locates at similar to 100 nm below perovskite surface. The energetics transformation and defect passivation promote charge transport in bulk perovskite layer and at perovskite/PCBM interface, suppressing both defect-assisted recombination and interface carrier recombination. As a result, an efficiency of 21.88% and a fill factor of 83.81% with excellent device stability are achieved, both values are the highest records for polycrystalline MAPbI(3) based p-i-n PSCs reported to date. The proposed new concept of synergetic defect passivation and energetic modification via additive provides a huge potential for further improvement of PSC performance.
Place, publisher, year, edition, pages
CELL PRESS , 2021. Vol. 5, no 2, p. 467-480
National Category
Condensed Matter Physics
Identifiers
URN: urn:nbn:se:liu:diva-174978DOI: 10.1016/j.joule.2020.12.009ISI: 000629204800016OAI: oai:DiVA.org:liu-174978DiVA, id: diva2:1544096
Note
Funding Agencies|National Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [21875067, 51811530011, 11604099]; Fundamental Research Funds for the Central Universities, Shanghai Rising-Star [19QA1403100]; East China Normal University (ECNU) Multifunctional Platform for Innovation; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linko ping University (Faculty Grant SFO Mat LiU) [200900971]; National Key Research and Development Program of China [2017YFA0206600]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [51773045, 21772030, 51922032]
2021-04-142021-04-142021-04-14Bibliographically approved