Control of Crystallinity in PbPc:C60 Blend Film and Application for Inverted Near-Infrared Organic Photodetector

Min-Soo Choi; Sangmin Chae; Hyo Jung Kim; Jang-Joo Kim

doi:10.1021/acsami.8b08803

Control of Crystallinity in PbPc:C₆₀ Blend Film and Application for Inverted Near-Infrared Organic Photodetector

ACS Appl Mater Interfaces. 2018 Aug 1;10(30):25614-25620. doi: 10.1021/acsami.8b08803. Epub 2018 Jul 20.

Authors

Min-Soo Choi¹, Sangmin Chae², Hyo Jung Kim², Jang-Joo Kim¹

Affiliations

¹ Department of Materials Science and Engineering, Research Institute of Advanced Materials , Seoul National University , Seoul 08826 , South Korea.
² Department of Organic Material Science and Engineering , Pusan National University , Busan 46241 , South Korea.

PMID: 29992818
DOI: 10.1021/acsami.8b08803

Abstract

Inverted near-infrared (NIR) organic photodetectors (OPDs) are required to combine the OPDs with an n-channel silicon-based integrated circuit. NIR absorption in the 930-960 nm range is important because the intensity of solar irradiation is low in this wavelength regime. Here, we controlled the crystallinity of lead(II) phthalocyanine (PbPc) in a PbPc:C₆₀ blend film to obtain NIR absorption. To form a triclinic phase responsible for NIR light absorption, a substrate was heated during fabrication and C₆₀ was used as a templating layer, as well as an electron extraction layer, for an inverted structure. NIR absorption near 950 nm was enhanced, and the structural properties of the film changed dramatically. The OPD with enhanced NIR absorption exhibited a responsivity of 244 mA/W and an external quantum efficiency of 31.1% at a reverse bias of -3 V and 970 nm. The OPD detectivity also increased to 9.01 × 10¹² and 1.36 × 10¹¹ cm Hz^1/2/W under a zero bias and a reverse bias of -3 V, respectively.

Keywords: bulk-heterojunction; inverted photodetector; lead phthalocyanine; near-infrared photodetector; substrate heating.