Thickness Effect on Structural Defect-Related Density of States and Crystallinity in P3HT Thin Films on ITO Substrates

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28140%2F18%3A63520893" target="_blank" >RIV/70883521:28140/18:63520893 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.acs.org/doi/10.1021/acs.jpcc.7b11651" target="_blank" >https://pubs.acs.org/doi/10.1021/acs.jpcc.7b11651</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpcc.7b11651" target="_blank" >10.1021/acs.jpcc.7b11651</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Thickness Effect on Structural Defect-Related Density of States and Crystallinity in P3HT Thin Films on ITO Substrates

Popis výsledku v původním jazyce

We report on a study of thickness effect on the formation of structural defect-related density of states (DOS) in the band gap of poly(3-hexylthiophene-2,5-diyl) (P3HT) thin films spincoated on ITO substrates. The energy-resolved electrochemical impedance spectroscopy and grazing-incidence wide-angle X-ray scattering were used to correlate the DOS with the degree of crystallinity in P3HT thin films. We found an exponential increase of the defect DOS in the band gap with increasing fraction of the amorphous phase when decreasing the film thickness. The exponent increases abruptly when reducing the thickness down to 30 nm, which indicates two thickness regions with different dynamics of the defect DOS formation driven by increasing the fraction of the amorphous phase. Moreover, we observed the co-existence of two P3HT polymorphic crystalline phases with different backbone spacings, which results in the appearance of a peculiar DOS satellite peak above the highest occupied molecular orbital. The volume of the minor, more dense, crystalline phase exhibits a thickness dependence with a maximum plateau around 40 nm. These results suggest an important effect of the substrate roughness on the crystallinity and polymorphism of P3HT thin films depending on the film thickness with general implications for polymer thin films

Název v anglickém jazyce

Thickness Effect on Structural Defect-Related Density of States and Crystallinity in P3HT Thin Films on ITO Substrates

Popis výsledku anglicky

We report on a study of thickness effect on the formation of structural defect-related density of states (DOS) in the band gap of poly(3-hexylthiophene-2,5-diyl) (P3HT) thin films spincoated on ITO substrates. The energy-resolved electrochemical impedance spectroscopy and grazing-incidence wide-angle X-ray scattering were used to correlate the DOS with the degree of crystallinity in P3HT thin films. We found an exponential increase of the defect DOS in the band gap with increasing fraction of the amorphous phase when decreasing the film thickness. The exponent increases abruptly when reducing the thickness down to 30 nm, which indicates two thickness regions with different dynamics of the defect DOS formation driven by increasing the fraction of the amorphous phase. Moreover, we observed the co-existence of two P3HT polymorphic crystalline phases with different backbone spacings, which results in the appearance of a peculiar DOS satellite peak above the highest occupied molecular orbital. The volume of the minor, more dense, crystalline phase exhibits a thickness dependence with a maximum plateau around 40 nm. These results suggest an important effect of the substrate roughness on the crystallinity and polymorphism of P3HT thin films depending on the film thickness with general implications for polymer thin films

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

JOURNAL OF PHYSICAL CHEMISTRY C

ISSN

1932-7447

e-ISSN

1932-7447

Svazek periodika

122

Číslo periodika v rámci svazku

11

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

7

Strana od-do

5881-5887

Kód UT WoS článku

000428356700006

EID výsledku v databázi Scopus

2-s2.0-85044464516