Phenyl Ethylammonium Iodide introduction into inverted triple cation perovskite solar cells for improved VOC and stability

• Published in: Organic electronics Vol. 93; p. 106121
• Main Authors: Yerramilli, Aditya S., Chen, Yuanqing, Gogoi, Banashree, Alford, T.L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2021
• Subjects: Inverted architecture; Moisture stability; Triple cation perovskite; Triple cation perovskite; Moisture stability; Inverted architecture
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2021.106121

The efficiency of more than 25% in organic-inorganic hybrid perovskite solar cells has made them very attractive in the pursuit of cheaper alternatives to Si-based devices. However, the stability of the perovskite solar cells was challenging, given their high susceptibility to moisture. Very few reports have emerged in this regard that investigated the influence of introducing large cations into a triple cation perovskite (TC-PVS), with several studies limited to single and dual cation perovskites. Further, the crystallization of TC-PVS on a polymer surface such as PEDOT is not straightforward, and their inclusion in inverted solar cell devices was limited. In this work, we investigated the impact of incorporating Phenyl ethyl ammonium cation into FAMACs triple cation composition. We demonstrated improvements in the crystallinity and more uniform coverage with little to no pinholes and smooth morphology for an optimum PEA amount of 1.67% in the precursor solution. The superior morphology, along with a passivation effect from a quasi 2D phase, led to increased photoluminescence and minority carrier lifetimes. Corresponding inverted photovoltaic devices prepared with PEA showed increased open-circuit voltage from 0.89 V for a control sample to 0.95 V for 1.67% PEA and 0.98 V for 5% PEA, doped devices in an inverted configuration. The efficiency, as a result, increased from 11.27% for a control device to 14.85% for a 1.67% PEA doped device. Further, PEA doped devices showed improved operational and thermal stability attributed to the higher moisture tolerance and light-soaking ability of the PEA doped TC-PVS compared to the undoped TC-PVS. [Display omitted] •Phenyl Ethylammonium Iodide (PEA) was used to dope triple cation perovskite for improved crystallinity and morphology.•Devices prepared in an inverted configuration on a PEDOT surface showed VOC improve from 0.89V to more than 0.95V.•A PCE of 14.85% for 1.67 % PEA doped device was demonstrated compared to 11.27% from a control device.•Higher operational stability was demonstrated with PEA devices retaining more than 85% PCE over 300 minutes.•Better thermal stability was demonstrated with PEA doped devices with an observed decay of 60% PCE over 30 days.