Unraveling the reasons behind lead phthalocyanine acting as a good absorber for near-infrared sensitive devices

• Published in: Scientific reports Vol. 12; no. 1; pp. 8810 - 12
• Main Authors: Kato, Masahiro, Yoshizawa, Hayato, Nakaya, Masato, Kitagawa, Yasutaka, Okamoto, Koichi, Yamada, Tomoaki, Yoshino, Masahito, Tanaka, Kentaro, Onoe, Jun
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 25.05.2022; Nature Publishing Group UK; Nature Portfolio
• Subjects: Absorption; I.R. radiation; Photons; Photovoltaic cells; Solar cells; Theoretical analysis
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-12990-z

Lead phthalocyanine (PbPc) is well known to be used as a good near-infrared (NIR) light absorber for organic solar cells (OSCs) and photodetectors. The monoclinic and triclinic phases have been understood to absorb the visible and NIR regions, respectively, so far. In the present study, we demonstrated from the absorption spectra and theoretical analysis that the visible band considerably originates from not only the monoclinic but also the amorphous and triclinic phases, and revealed the exciton dynamics in the PbPc film from static/time-resolved photoluminescence (PL), which are first reported. By comparing the external quantum efficiency between PbPc- and ZnPc-based OSCs in relation to their structure, morphology, and optical (absorption and PL) characteristics, we unraveled the reasons behind the PbPc film used as a good absorber for NIR-sensitive devices.