TY - JOUR
T1 - High-Performance Photomultiplication Photodiode with a 70 nm-Thick Active Layer Assisted by IDIC as an Efficient Molecular Sensitizer
AU - Neethipathi, Deepan Kumar
AU - Ryu, Hwa Sook
AU - Jang, Min Su
AU - Yoon, Seongwon
AU - Sim, Kyu Min
AU - Woo, Han Young
AU - Chung, Dae Sung
N1 - Funding Information:
This research was supported by Space Core Technology Development Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (Grant no. NRF-2014M1A3A3A02034707). This work was also supported by the National Research Foundation (NRF) of Korea (NRF-2016M1A2A2940911).
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/6/12
Y1 - 2019/6/12
N2 - Here, a smart strategy for decreasing the active layer thickness of the organic photodiode down to 70 nm is demonstrated by utilizing a trap-assisted photomultiplication mechanism with the optimized chemical composition. Despite the presence of a high dark current, dramatically enhanced external quantum efficiency (EQE) via photomultiplication can allow significantly reduced active layer thickness, yielding high detectivity comparable to that of conventional Si. To achieve this, a spatially confined and electrically isolated optical sensitizer, 2,2′-((2Z,2′Z)-((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (IDIC) was introduced strategically between a hole transport active layer and a cathode. A nonfullerene acceptor, IDIC, turned out to be a much more efficient sensitizer than the conventional fullerene-based acceptors, as confirmed by the effective lowering of the Schottky barrier under illumination, as well as the highest EQE exceeding 130 000%. Due to its favorable electronic structure as well as two-dimensional molecular structure, a high detectivity over 1012 Jones was successfully demonstrated while maintaining the active layer thickness as 70 nm.
AB - Here, a smart strategy for decreasing the active layer thickness of the organic photodiode down to 70 nm is demonstrated by utilizing a trap-assisted photomultiplication mechanism with the optimized chemical composition. Despite the presence of a high dark current, dramatically enhanced external quantum efficiency (EQE) via photomultiplication can allow significantly reduced active layer thickness, yielding high detectivity comparable to that of conventional Si. To achieve this, a spatially confined and electrically isolated optical sensitizer, 2,2′-((2Z,2′Z)-((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (IDIC) was introduced strategically between a hole transport active layer and a cathode. A nonfullerene acceptor, IDIC, turned out to be a much more efficient sensitizer than the conventional fullerene-based acceptors, as confirmed by the effective lowering of the Schottky barrier under illumination, as well as the highest EQE exceeding 130 000%. Due to its favorable electronic structure as well as two-dimensional molecular structure, a high detectivity over 1012 Jones was successfully demonstrated while maintaining the active layer thickness as 70 nm.
KW - detectivity
KW - external quantum efficiency
KW - nonfullerene acceptor
KW - photomultiplication
KW - polymer photodetector
UR - http://www.scopus.com/inward/record.url?scp=85066477344&partnerID=8YFLogxK
U2 - 10.1021/acsami.9b01090
DO - 10.1021/acsami.9b01090
M3 - Article
C2 - 31141329
AN - SCOPUS:85066477344
SN - 1944-8244
VL - 11
SP - 21211
EP - 21217
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
IS - 23
ER -