Conjugated oxazole‐based interfacial materials for efficient and stable inverted polymer solar cell with an efficiency of 16.52%. (5th July 2022)

• Record Type: Journal Article
• Authors: Sekar, Sankar; Kumar, K. Ashok; Sree, Vijaya Gopalan; Gnanamoorthy, G.; Lee, Sejoon; Kim, Deuk Young; Manikandan, Ramalingam
• Is Part Of: International journal of energy research. Volume 46:Number 12(2022)
• Page Start: 16791
• Page End: 16798
• Publication Date: 2022-07-05
• Subjects: high current density -- high PCE -- interfacial layer -- inverted polymer solar cells -- stability; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.8342
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: Organic solar cells (OSCs) using non‐fullerene acceptors have delivered the highest efficiencies in the overall reported literatures. In order to improve the efficiency and stability of OSCs, great efforts are being made in designing and synthesizing new materials. Inverted OSCs were fabricated using three commercially available and inexpensive materials, 5‐methylbenzoxazole (E1 ), 2‐(4‐biphenyl)‐5‐phenyloxazole (E2 ), and 4‐bis(5‐phenyl‐2‐oxazolyl)benzene (E3 ), as an interlayer between zinc oxide and the active layer. The new interlayer materials enhance the carrier injection/extraction properties and thus, the polymer solar cells (PSCs) exhibited an improved J SC and power conversion efficiency (PCE). PSCs showed an improved J SC of 27.18 from 24.88 mA/cm 2 with the introduction of E3 . The new interlayer, E3 in particular, forms well‐aligned cascading energy levels between the PM6:Y6 active layer and zinc oxide layer. These cascading energy levels reduce the energy barrier for electron injection and collection at the interface. Thus, the PCE of devices reached a remarkable 16.52% using interlayer at the ZnO/active layer interface. The devices also exhibited improved device stability under continuous illumination, annealing, and high humidity. Abstract : In order to improve efficiency and stability of non‐fullerene acceptor based PSCs, we have used three commercially available and inexpensive materials, E1, E2, and E3, as interlayer between zinc oxide and active layer in inverted OSCs. The new interlayer materials enhance the carrier injection/extraction properties and thus the PSCs exhibited an improved J SC of 27.18 mA/cm 2 and PCE of 16.52%. The new interlayer, E3 in particular, forms a well‐aligned cascade energy levels between the active layer and zinc oxide layer. This cascading energy levels reduce the energy barrier for electron injection and collection at the interface. The devices also exhibited improved device stability under continuous illumination, annealing and high humidity.