Rana, Aniket and Kumar, Amit and Chand, Suresh and Singh, Rajiv K (2019) Hole transport layer influencing the charge carrier dynamics during the degradation of organic solar cells. Journal of Applied Physics , 125 (5). 053102- 053110. ISSN 0021-8979

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Abstract

Here, we demonstrate the effect of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and molybdenum trioxide (MoO3) hole transport layers (HTLs) on degradation of the bulk-heterojunction organic solar cell (OSC) with the combination of two active layers poly(3-hexylthiophene) and poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] The study is performed for unencapsulated conventional structure OSCs exposed to the ambient dark condition. In the self-life test situation, it is found that PEDOT:PSS based devices show an initial higher short circuit current and subsequent faster degradation with time in comparison to the MoO3 based devices. The effects of these HTLs have been shown in terms of better charge extraction and a decrease in the shunt resistance as well as the bulk resistance of the active layer. The charge carrier generation probability evaluated from photocurrent data shows the dominant impact of active layer degradation rather than the oxidation of a top electrode under the ambient condition. This suggested mechanism is further supported by impedance spectroscopy as well as the evaluated transit time, global mobility, and exciton dissociation probability, establishing that the degradation does not much affect the transport property of the active material. Rather, it affects more the carrier generation rate. The low hole extraction barrier in PEDOT:PSS based devices show small transit time and high global mobility compared to MoO3. It is found that during the degradation process, the bulk resistance of the device significantly increases, which reduces the diffusion current in the device.

Item Type: Article
Additional Information: Copyright for this article belongs to M/s American Institute of Physics.
Subjects: Applied Physics/Condensed Matter
Divisions: UNSPECIFIED
Depositing User: Mr. Yogesh Joshi
Date Deposited: 19 Aug 2026 11:20
Last Modified: 19 Aug 2026 11:20
URI: https://npl.csircentral.net/id/eprint/4232

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