Organic Bilayer Photovoltaics for Efficient Indoor Light Harvesting. Issue 3 (15th December 2021)

• Record Type: Journal Article
• Authors: Park, Song Yi; Labanti, Chiara; Luke, Joel; Chin, Yi‐Chun; Kim, Ji‐Seon
• Is Part Of: Advanced energy materials. Volume 12:Issue 3(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-15
• Subjects: organic solar cells -- indoor organic photovoltaics -- bilayer‐heterojunction -- bulk‐heterojunction -- light‐soaking; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202103237
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Indoor organic photovoltaics (OPVs) are a potential niche application for organic semiconductors due to their strong and well‐matched absorption with the emission of indoor lighting. However, due to extremely low photocurrent generation, the device parameters critical for efficient indoor OPVs differ from those under 1 Sun conditions. Herein, these critical device parameters—recombination loss and shunt resistance ( R sh )—are identified and it is demonstrated that bilayer OPVs are suitable for indoor PV applications. Compared to bulk‐heterojunction (BHJ), the open‐circuit voltage loss of bilayer devices under low light intensities is much smaller, consistent with a larger surface photovoltage response, indicating suppressed recombination losses. The bilayer devices show a higher fill factor at low light intensities, resulting from high R sh afforded by the ideal interfacial contacts between the photoactive and the charge transport layers. The high R sh enables bilayer devices to perform well without a light‐soaking process. Finally, the charge carriers are extracted rapidly in bilayers, which are attributed to strongly suppressed trap states possibly induced by isolated domains and non‐ideal interfacial contacts in BHJs. This study highlights the excellent suitability of bilayer OPVs for indoor applications and demonstrates the importance of device architecture and interfacial structures for efficient indoor OPVs. Abstract : The excellent suitability of bilayer organic photovoltaic devices for efficient indoor‐light harvesting is demonstrated. Thanks to ideal interfacial contacts between photoactive and charge transport layers and minimized isolated donor and/or acceptor domains, bilayer devices show much smaller open‐circuit voltage loss and high shunt resistance, leading to enhanced fill factor and max power output without light soaking.