Premium
Unifying Energetic Disorder from Charge Transport and Band Bending in Organic Semiconductors
Author(s) -
Karki Akchheta,
Wetzelaer GertJan A. H.,
Reddy Gollapalli Narayana Manjunatha,
Nádaždy Vojtech,
Seifrid Martin,
Schauer Franz,
Bazan Guillermo C.,
Chmelka Bradley F.,
Blom Paul W. M.,
Nguyen ThucQuyen
Publication year - 2019
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201901109
Subject(s) - materials science , organic semiconductor , chemical physics , charge (physics) , polymer , charge carrier , semiconductor , condensed matter physics , conjugated system , relaxation (psychology) , band bending , nanotechnology , optoelectronics , chemistry , physics , psychology , social psychology , quantum mechanics , composite material
Characterizing the density of states (DOS) width accurately is critical in understanding the charge‐transport properties of organic semiconducting materials as broader DOS distributions lead to an inferior transport. From a morphological standpoint, the relative densities of ordered and disordered regions are known to affect charge‐transport properties in films; however, a comparison between molecular structures showing quantifiable ordered and disordered regions at an atomic level and its impact on DOS widths and charge‐transport properties has yet to be made. In this work, for the first time, the DOS distribution widths of two model conjugated polymer systems are characterized using three different techniques. A quantitative correlation between energetic disorder from band‐bending measurements and charge transport is established, providing direct experimental evidence that charge‐carrier mobility in disordered materials is compromised due to the relaxation of carriers into the tail states of the DOS. Distinction and quantification of ordered and disordered regions of thin films at an atomic level is achieved using solid‐state NMR spectroscopy. An ability to compare solid‐state film morphologies of organic semiconducting polymers to energetic disorder, and in turn charge transport, can provide useful guidelines for applications of organic conjugated polymers in pertinent devices.