High-Detectivity Non-Fullerene Organic Photodetectors Enabled by a Cross-Linkable Electron Blocking Layer
- 11 September 2020
- journal article
- research article
- Published by American Chemical Society (ACS) in ACS Applied Materials & Interfaces
- Vol. 12 (40), 45092-45100
- https://doi.org/10.1021/acsami.0c13833
Abstract
The anode interlayer plays a critical role in the performance of organic photodetectors, which requires sufficient electron-blocking ability to simultaneously attain high photo-current and low dark current. Here we developed two cross-linkable polymers, which can be deposited on the top of the widely used poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and form robust layer that can effectively suppress the electron injection from the anode under reverse bias. The optimized device with the resulted cross-linkable XP2 exhibited the lowest dark current density of 5.81×10^–9 A/cm2 at –0.1 V, which is about two orders of magnitude lower than the control devices. A remarkable responsivity of 0.5 A/W and a detectivity of >1×10^13 Jones at a near-infrared wavelength of 800 nm were achieved. Of particular importance is that the resulting device exhibited a linear dynamic range of > 135 dB associated with a high working frequency that is shorter than typical commercial digital imagers. The planar heterojunction devices demonstrate that the dark current is closely correlated to the charge generation, which relied on the highest occupied molecular orbital energy levels of the developed cross-linked interlays. The Mott-Schottky analysis revealed that the optimized cross-linked interlayer increased the depletion width of the devices.Keywords
Funding Information
- National Natural Science Foundation of China (51933003)
- Basic and Applied Basic Research Major Program of Guangdong Province (2019B030302007)
- Program for Science and Technology Development of Dongguan (2019622163009)
- Science and Technology Program of Guangdong (2020A1515011028)
This publication has 48 references indexed in Scilit:
- High‐Performance All‐Polymer Photoresponse Devices Based on Acceptor–Acceptor Conjugated PolymersAdvanced Functional Materials, 2016
- Organic Photodiodes: The Future of Full Color Detection and Image SensingAdvanced Materials, 2016
- High‐Performance, Fullerene‐Free Organic Photodiodes Based on a Solution‐Processable IndigoAdvanced Materials, 2015
- Disorder‐Induced Open‐Circuit Voltage Losses in Organic Solar Cells During Photoinduced Burn‐InAdvanced Energy Materials, 2015
- Solution-processable metal oxides/chelates as electrode buffer layers for efficient and stable polymer solar cellsEnergy & Environmental Science, 2014
- Investigating the Influence of Interfacial Contact Properties on Open Circuit Voltages in Organic Photovoltaic Performance: Work Function Versus SelectivityAdvanced Energy Materials, 2013
- Sensitivity of the Mott–Schottky Analysis in Organic Solar CellsThe Journal of Physical Chemistry C, 2012
- Origin of the dark-current ideality factor in polymer:fullerene bulk heterojunction solar cellsApplied Physics Letters, 2011
- High-Detectivity Polymer Photodetectors with Spectral Response from 300 nm to 1450 nmScience, 2009
- Molecular and Morphological Influences on the Open Circuit Voltages of Organic Photovoltaic DevicesJournal of the American Chemical Society, 2009