Semitransparent Inverted Organic Solar Cells Using an Oxide/metal/oxide Transparent Anode

Abstract

Semitransparent inverted bulk-heterojunction solar cells were fabricated on an ITO/glass substrate utilizing oxide/metal/oxide transparent anode. The device structure was glass/ITO/PFN/PTB7:PC 71 BM/MoO 3 /Au/MoO 3 . The semitransparent solar cell showed a transparency of 44% at 550 nm and bifacial power generation at both front and backside illumination. The power conversion efficiencies (PCEs) with light illuminated from ITO or Au/MoO 3 side were 2.8% and 2.3%, respectively. Fabrication of stacking structure of two separated solar cells was further demonstrated to harvest an increased amount of photons and enhance the PCEs. The stacked cells showed a transmittance of 17 % at 550 nm and improved PCE of 3.3% when connecting two cells in parallel. Keyword: semitransparent organic solar cells, bulk-heterojunction, PTB7, PC71BM, oxide/metal/oxide electrode

Fabrication of Flexible and Semitransparent PTB7:PC₇₁BM Organic Solar Cells

“…5(a). In this case, the 10 nm-thick MoO 3 layer was used as a buffer layer, whereas the 20 nm-thick top capping MoO 3 layer was deposited to enhance transmittance in the visible region [12]. A photograph of the cell is shown in Fig.…”

“…1(a). The fabrication process employed herein is based on our previously reported method [12] using the following procedures.…”

“…In addition to this type of solar cell, interest in semitransparent BHJ solar cells [7] has increased because of their possible use in new applications such as multi-junction solar photovoltaics [8] and vinyl greenhouse. Many inverted solar cells have been reported that use transparent top anodes, such as thin metals [6], oxide/metal/oxide trilayer [9][10][11][12], carbon nanotube sheets [13], graphene [14], and silver nano-networks [15]. Most notably, the oxide/metal/oxide trilayer is promising because of its good optical and electrical properties [16], as well as its easy fabrication procedure, in which three layers are evaporated sequentially in a vacuum chamber.…”

“…We have recently reported a semitransparent BHJ solar cell based on PTB7 and PC 71 BM blend films. The solar cell was fabricated on a glass substrate and exhibited PCE as high as 2.8 % [12]. Given the desirability of developing solar cells with flexible substrates and our previous success with semitransparent BHJ solar cells, this report details the fabrication and performance of semitransparent BHJ solar cells utilizing trilayer transparent anodes on flexible PET substrates.…”

Recent Progress in Semitransparent Organic and Perovskite Solar Cells

“…As the active area increases to 2.25 cm 2 , the PCE of the ZAZ top electrode-based devices decreased to 2%, while the devices based on ITO top electrode exhibited a PCE of only 1.5%, which is 30% lower than ZAZ cells. Fujii et al [77] reported semitransparent inverted bulk heterojunction solar cells, utilizing MoO 3 / Au/MoO 3 transparent anode, in which the thickness of Au was 15 nm and MoO 3 layers sandwiching the Au film were 10 nm. The device structure is glass/ITO/PFN/PTB7:PC 71 BM/MoO 3 / Au/MoO 3 .…”