Rana, Aniket and Sharma, Chhavi and Prabhu, Deepak D. and Kumar, Mahesh and Karuvath, Yoosaf and Das, Suresh and Chand, Suresh and Singh, Rajiv K. (2018) Revealing charge carrier dynamics in squaraine: [6,6]-phenyl-C 71-butyric acid methyl ester based organic solar cells. AIP Advances, 8 (4). 045302-045311. ISSN 2158-3226

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Ultrafast charge carrier dynamics as well as the generation of polaron pair in squaraine (SQ) and squaraine:[6,6]-phenyl-C 71-butyric acid methyl ester (SQ:PCBM71) have been studied using ultrafast transient absorption spectroscopy (UTAS). The current study reveals that the pure SQ exhibits the creation of singlet and triplet states; however, incorporation of PCBM71 in SQ results in the formation of polaron pairs with similar to 550ps lifetime, which in turn leads to the creation of free electrons in the device. We show that the considerable increment in monomolecular and bimolecular recombination in SQ:PCBM71 compared to pure SQ which describes the interfacial compatibility of SQ and PCBMC71 molecules. The present work not only provides the information about the carrier generation in SQ and SQ:PCBM71 but also gives the facts relating to the effect of PCBM71 mixing into the SQ which is very significant because the SQ has donor-acceptor-donor (D-A-D) structure and mixing one more acceptor can introduce more complex recombinations in the blend. These findings have been complimented by the charge transport study in the device using impedance spectroscopy. The various important transport parameters are transit time (tau(t)), diffusion constant (D-n), global mobility (mu) and carrier lifetime (tau(r)). The values of these parameters are 26.38 mu s, 4.64x10(-6) cm(2)s(-1), 6.12x10(-6) cm(2)V(-1)s(-1) and 399 mu s, respectively. To the best of our knowledge such study related to SQ is not present in the literature comprehensively.

Item Type: Article
Additional Information: Copyright for this article belongs to M/s American Institute of Physics.
Subjects: Materials Science
Applied Physics/Condensed Matter
Nanoscience/ Nanotechnology
Depositing User: Users 27 not found.
Date Deposited: 17 Dec 2019 08:20
Last Modified: 17 Dec 2019 08:20
URI: http://npl.csircentral.net/id/eprint/3797

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