Gwangju Institute of Science and Technology (GIST) has announced they have developed a new module architecture capable of improving geometrical fill factors up to 90% and power conversion efficiencies (PCEs) of printed organic photovoltaic (OPV) modules up to 7.5% in 4.15 cm2.
A research group led by Kwanghee Lee (Professor, School of Materials Science & Engineering, GIST) has designed a new monolithic interconnection that enables facile and efficient module fabrication without patterning electron/hole transport layers and producing considerable aperture loss.
By using an innovative series connection concept based on a charge recombination characteristic that occurs at the contacts between charge transport layers (CTLs), large-area OPV modules can be more easily fabricated compared to conventional OPV modules because the complicated patterning processes of CTLs are eliminated.
Therefore, highly efficient printed OPV modules were successfully demonstrated with a certificated PCE of 7.5% in 4.15 cm2 under Air Mass (AM) 1.5 condition.
GIST considers that this result is very important because printed OPV modules approaching the 7.5% module efficiency represent a remarkable progress toward the commercialisation of OPVs.
Figure: GIST - Large-area printed organic photovoltaics
According to the researchers OPV research has largely been conducted on small-area devices (< 0.2 cm2) using lab-scale spin-coating processing which is not compatible with a roll-to-roll process. Although impressive progress made over the last few decades has contributed to the development of large-area modules using printing technology, there have been few reports that satisfy both large area and high efficiency in the fabrication of OPV modules until now.
GIST are confident that the combination of their module architecture and printing techniques will accelerate the practical development of OPV and ultimately lead to the successful commercialisation of OPVs in the near future.
A series connection architecture for large-area organic photovoltaic modules with a 7.5% module efficiency
Soonil Hong | Hongkyu Kang | Geunjin Kim | Seongyu Lee | Seok Kim | Jong-Hoon Lee | Jinho Lee | Minjin Yi | Junghwan Kim | Hyungcheol Back | Jae-Ryoung Kim | Kwanghee Lee
Nature Communications 7, Article number: 10279 | doi:10.1038/ncomms10279
Received 04 August 2015 | Accepted 25 November 2015 | Published 05 January 2016
The fabrication of organic photovoltaic modules via printing techniques has been the greatest challenge for their commercial manufacture. Current module architecture, which is based on a monolithic geometry consisting of serially interconnecting stripe-patterned subcells with finite widths, requires highly sophisticated patterning processes that significantly increase the complexity of printing production lines and cause serious reductions in module efficiency due to so-called aperture loss in series connection regions. Herein we demonstrate an innovative module structure that can simultaneously reduce both patterning processes and aperture loss. By using a charge recombination feature that occurs at contacts between electron- and hole-transport layers, we devise a series connection method that facilitates module fabrication without patterning the charge transport layers. With the successive deposition of component layers using slot-die and doctor-blade printing techniques, we achieve a high module efficiency reaching 7.5% with area of 4.15 cm2.