biostudies-literatureUnknown8(1)Lindh EMThe light-emitting electrochemical cell (LEC) is functional at substantial active-layer thickness, and is as such heralded for being fit for low-cost and fault-tolerant solution-based fabrication. We report here that this statement should be moderated, and that in order to obtain a strong luminous output, it is fundamentally important to fabricate LEC devices with a designed thickness of the active layer. By systematic experimentation and simulation, we demonstrate that weak optical microcavity effects are prominent in a common LEC system, and that the luminance and efficiency, as well as the emission color and the angular intensity, vary in a periodic manner with the active-layer thickness. Importantly, we demonstrate that high-performance light-emission can be attained from LEC devices with a significant active-layer thickness of 300 nm, which implies that low-cost solution-processed LECs are indeed a realistic option, provided that the device structure has been appropriately designed from an optical perspective.Scientific reports6970https://www.ebi.ac.uk/biostudies/studies/S-EPMC5934366biostudies-literatureThe Weak Microcavity as an Enabler for Bright and Fault-tolerant Light-emitting Electrochemical Cells.PMC5934366Mindemark JLundberg PEdman LLindh EMLanz TfalseThe Weak Microcavity as an Enabler for Bright and Fault-tolerant Light-emitting Electrochemical Cells.The light-emitting electrochemical cell (LEC) is functional at substantial active-layer thickness, and is as such heralded for being fit for low-cost and fault-tolerant solution-based fabrication. We report here that this statement should be moderated, and that in order to obtain a strong luminous output, it is fundamentally important to fabricate LEC devices with a designed thickness of the active layer. By systematic experimentation and simulation, we demonstrate that weak optical microcavity effects are prominent in a common LEC system, and that the luminance and efficiency, as well as the emission color and the angular intensity, vary in a periodic manner with the active-layer thickness. Importantly, we demonstrate that high-performance light-emission can be attained from LEC devices with a significant active-layer thickness of 300 nm, which implies that low-cost solution-processed LECs are indeed a realistic option, provided that the device structure has been appropriately designed from an optical perspective.2018-01-01T00:00:00Z2018 May2025-05-29T21:51:36.288Z2025-05-29T21:51:36.288ZS-EPMC59343662972506110.1038/s41598-018-25287-x