{"id":75,"date":"2020-05-30T10:02:28","date_gmt":"2020-05-30T10:02:28","guid":{"rendered":"http:\/\/blog.wias-berlin.de\/nano-opto-electronics\/?p=75"},"modified":"2024-04-02T06:56:25","modified_gmt":"2024-04-02T06:56:25","slug":"s-shaped-iv-curves-in-organic-semiconductors","status":"publish","type":"post","link":"https:\/\/blog.wias-berlin.de\/nano-opto-electronics\/2020\/05\/30\/s-shaped-iv-curves-in-organic-semiconductors\/","title":{"rendered":"S-shaped IV-curves in organic semiconductors"},"content":{"rendered":"\n
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Simulated Joule heat density [W\/cm^3] in an organic thin-film transistor <\/figcaption><\/figure>\n\n\n\n
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Simulated current\u2013voltage characteristics using the electrothermal drift\u2013diffusion model for different reference mobilities<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

Organic semiconductors show a complex interplay between charge-carrier and heat flow. In particular, due to Joule self-heating the temperature in an organic device increases, which in turn leads to an increase in conductivity due to temperature activated hopping transport. A positive feedback loop arises. In recent publications by our colleagues from the Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP), S-shaped current-voltage characteristics of organic devices have been observed in experiments. In previous work, we have modeled this interplay via a coarse thermistor model for the net current and heat flow (see here<\/a>).<\/p>\n\n\n\n

In order to give a more detailed description of the processes, we extended our drift-diffusion simulation tool ddfermi<\/a> to take self-heating and the positive feedback in the mobility laws, that are usually used for organic materials, into account. The details can be found in a recently published paper<\/a> with out partners from the IAPP and the company m4sim GmbH in the Journal of Computational Electronics. <\/p>\n\n\n\n

In the paper, an electrothermal drift\u2013diffusion model for organic semiconductor devices with Gauss\u2013Fermi statistics and positive temperature feedback for the charge carrier mobilities is introduced. We apply temperature-dependent Ohmic contact boundary conditions for the electrostatic potential and discretize the system by a finite volume based generalized Scharfetter\u2013Gummel scheme. Using path-following techniques, we demonstrate that the model exhibits S-shaped current\u2013voltage curves with regions of negative differential resistance.<\/p>\n\n\n\n

Drift\u2013diffusion simulation of S-shaped current\u2013voltage relations for organic semiconductor devices<\/strong>
Duy Hai Doan, Axel Fischer, J\u00fcrgen Fuhrmann, Annegret Glitzky & Matthias Liero
Journal of Computational Electronics (2020)
https:\/\/doi.org\/10.1007\/s10825-020-01505-6<\/a><\/p>\n\n\n\n

Open Access funding provided by Projekt DEAL. The work was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany\u2019s Excellence Strategy\u2014The Berlin Mathematics Research Center MATH+ (EXC-2046\/1, Project ID: 390685689) in transition project SE18, Project AA2-1 and AA2-6 and the DFG Project EFOD (Grant No. RE 3198\/6-1).<\/p>\n","protected":false},"excerpt":{"rendered":"

Organic semiconductors show a complex interplay between charge-carrier and heat flow. In particular, due to Joule self-heating the temperature in an organic device increases, which in turn leads to an increase in conductivity due to temperature activated hopping transport. A positive feedback loop arises. In recent publications by our colleagues from the Dresden Integrated Center … Continue reading S-shaped IV-curves in organic semiconductors<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":116,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,4],"tags":[],"class_list":["post-75","post","type-post","status-publish","format-standard","hentry","category-organic-electronics","category-self-heating"],"_links":{"self":[{"href":"https:\/\/blog.wias-berlin.de\/nano-opto-electronics\/wp-json\/wp\/v2\/posts\/75","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.wias-berlin.de\/nano-opto-electronics\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.wias-berlin.de\/nano-opto-electronics\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.wias-berlin.de\/nano-opto-electronics\/wp-json\/wp\/v2\/users\/116"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.wias-berlin.de\/nano-opto-electronics\/wp-json\/wp\/v2\/comments?post=75"}],"version-history":[{"count":9,"href":"https:\/\/blog.wias-berlin.de\/nano-opto-electronics\/wp-json\/wp\/v2\/posts\/75\/revisions"}],"predecessor-version":[{"id":131,"href":"https:\/\/blog.wias-berlin.de\/nano-opto-electronics\/wp-json\/wp\/v2\/posts\/75\/revisions\/131"}],"wp:attachment":[{"href":"https:\/\/blog.wias-berlin.de\/nano-opto-electronics\/wp-json\/wp\/v2\/media?parent=75"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.wias-berlin.de\/nano-opto-electronics\/wp-json\/wp\/v2\/categories?post=75"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.wias-berlin.de\/nano-opto-electronics\/wp-json\/wp\/v2\/tags?post=75"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}