Poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] MEH-PPV polymer-based heterojunction for organic electronics: Analysis using impedance spectroscopy
International Journal of Modern Physics B, cilt.39, sa.28, 2025 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 39 Sayı: 28
- Basım Tarihi: 2025
- Doi Numarası: 10.1142/s0217979225502534
- Dergi Adı: International Journal of Modern Physics B
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC, zbMATH
- Anahtar Kelimeler: capacitance–voltage measurements, Cole–Cole relaxation, dielectric properties, Impedance spectroscopy, interface states, organic semiconductor
- Isparta Uygulamalı Bilimler Üniversitesi Adresli: Hayır
Özet
The electrical and dielectric properties of an Au/MEH-PPV/p-Si/Al heterojunction were investigated using impedance spectroscopy. The impedance spectra revealed Cole–Cole-type relaxation with a fractal exponent (α) of 0.85, indicating nonideal charge dynamics modeled with a constant phase element. A remarkably high dielectric constant (ε′) of 45 was measured at 1kHz, highlighting the device’s potential for charge storage applications. At frequencies above 1MHz, the device exhibited negative capacitance (NC), a signature of dynamic inductive effects arising from charge carrier trapping and relaxation at the organic–inorganic interface. This behavior corresponds to an L–C resonance near 1MHz, which is also marked by a minimum in the dielectric loss (tan δ). These findings demonstrate that the device’s frequency response is governed by a complex interplay of interface states, dipole polarization and series resistance.