Degradation analysis of doped organic p-n heterojunction charge generation layers by impedance and optical spectroscopy
| Autor: | M.-H. Kim, E.-J. Jang, J. Lee, J.-H. Lee, Y.-J. Lim, Akpeko Gasonoo, Y. Choi |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Tandem Renewable Energy Sustainability and the Environment business.industry Materials Science (miscellaneous) Doping Energy Engineering and Power Technology Heterojunction Capacitance Molybdenum trioxide Organic semiconductor chemistry.chemical_compound Fuel Technology Nuclear Energy and Engineering chemistry Optoelectronics Rubidium carbonate business Spectroscopy |
| Zdroj: | Materials Today Energy. 21:100794 |
| ISSN: | 2468-6069 |
| DOI: | 10.1016/j.mtener.2021.100794 |
| Popis: | Investigation of the long-term stability of charge generation layers (CGLs) provides a fundamental and an essential approach in achieving highly efficient tandem organic electronic devices. Thus, in this foremost study, the degradation mechanism of electrically aged organic p-n heterojunction CGLs has been investigated by impedance and optical spectroscopy. Rubidium carbonate (Rb 2CO3)–doped 2,2,2-(1,3,5-benzinetriyl)-tris(1-phenyl-1H-benzimidazole) (TPBi) and molybdenum trioxide (MoO3 )–doped 1,4-bis[N-(1-naphthyl)-N′-phenylamino]-4,4′-diamine (NPB) are used as the n-type and p-type organic semiconductors , respectively. A detailed analysis from capacitance-frequency ( C–F) and capacitance-voltage (C–V) characteristics reveals reduced charge generation and 19.6% reduction in the geometric capacitance of the CGL after electrical aging. Reduced peak intensity from UV–Vis–NIR spectra of the aged CGL points to 21.4% charge transfer complex decomposition of the Rb2CO3 -doped TPBi. We propose that the rate-limiting step of charge generation in the CGL is caused by the electron transport in the TPBi:Rb 2CO3 layer and not the charge generation itself at the TPBi:Rb2CO3/NPB:MoO3 heterojunction. This simple, comprehensive, and non-destructive technique facilitates a crucial analysis that underpins the mechanism of device degradation and further provides a fundamental approach in developing highly stable CGLs for efficient organic electronic devices. |
| Databáze: | OpenAIRE |
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