Optimizing the organic solar cell efficiency: Role of the active layer thickness

APAYDIN D. H., Yildiz D. E., ÇIRPAN A., TOPPARE L.

SOLAR ENERGY MATERIALS AND SOLAR CELLS, vol.113, pp.100-105, 2013 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 113
  • Publication Date: 2013
  • Doi Number: 10.1016/j.solmat.2013.02.003
  • Journal Name: SOLAR ENERGY MATERIALS AND SOLAR CELLS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.100-105
  • Keywords: Active layer optimization, Organic solar cells, Space charge limited current, SOLUTION PROCESSABLE BENZOTRIAZOLE, POLYMER, PERFORMANCE, BLENDS, COPOLYMERS, DEPENDENCE, MORPHOLOGY, FLUORENE, DEVICES
  • Middle East Technical University Affiliated: Yes

Abstract

A 2-dodecyl benzotriazole and 9,9-dioctylfluorene containing alternating conjugated polymer, poly((9,9-dioctylfluorene)-2,7-diyl-(4,7-bis(thien-2-yl) 2-dodecyl-benzo[1,2,3]triazole)) (PFTBT), was blended with PCBM (1:1, w/w) and spin coated on ITO substrates using varying rotational speeds to obtain different active layer thicknesses. J-V characteristics of the constructed devices were investigated both in dark and under simulated sunlight (AM 1.5G, 100 mW/cm(2)). For the determination of hole mobilities the space charge limited current (SCLC) method was used and found as 1.69 x 10(-6) cm(2)/Vs. In addition, the power conversion efficiency (PCE) of the devices was varied according to active layer thickness and the best power conversion efficiency was recorded as 1.06%. Moreover, incident-photon-to-current-efficiency (IPCE) measurements were carried out and the best efficiency was found to be 51%. Morphology of the active layers was probed using AFM and TEM techniques. (C) 2013 Elsevier B.V. All rights reserved.