Impact of voltage and frequency on electrical characteristics of MIS capacitors with triphenylamine layer

• Published in: Physica. B, Condensed matter Condensed matter, 2025-01, Vol.696, p.416606, Article 416606
• Main Authors: Izmirli, Selcuk, Cavdar, Sukru, Oruc, Pınar, Eymur, Serkan, Tuğluoğlu, Nihat
• Format: Article
• Language: English
• Subjects: Active interface trap density; MIS-Type capacitor; Series resistance; TPA
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2024.416606

This study examines the effect of triphenylamine (TPA) interlayers on the electrical properties of Al/TPA/p-Si metal-interlayer/insulator material-semiconductor (MIS) capacitors. Using Gaussian software, TPA molecular structure was optimized, and HOMO-LUMO energy levels were simulated. Capacitance-conductance-voltage (C-G-V) measurements were performed at room temperature over −4 V to +4 V and 50 kHz–700 kHz. AFM and SEM analysis showed TPA films were smooth with a uniform thickness of about 178 nm. The C-V characteristics revealed a frequency-dependent decrease in capacitance, indicating a continuous distribution of interface states. Barrier height (ΦB) increased from 0.305 eV at 50 kHz to 0.655 eV at 700 kHz, while the active interface trap density (Dit) decreased from 6.73 × 1012 eV−1 cm−2 to 3.23 × 1011 eV−1 cm−2. Additionally, the accumulating region exhibited low series resistance values (between 6.88 and 8.44 Ω). These results suggest that TPA thin films are effective for MIS capacitors.