Channel characteristics of ferroelectric organic High-K dielectric asymmetric metal insulator semiconductor capacitor

Abstract

In the present work, it is demonstrated that an asymmetric organic MIS (AMIS) capacitor utilizing sandwiched ferroelectric material between high k-dielectric as an insulator and pentacene as an active semiconductor can be used for a wide range of sensing applications. The capacitive test structure is simpler in fabrication and characterization and is less sensitive to defect states since it utilizes a strong accumulation region. The polarization behavior of the ferroelectric materials enables higher charge density in the channel thereby reducing channel resistance and thus increasing the channel capacitance. This property of the Ferro-based AMIS structure enables the extraction of OTFT parameters and also serves as a platform for sensing applications. The use of high-k dielectric material both as an insulator and buffer layer makes the technique more robust against lattice mismatch and high-power dissipation. The channel characteristics are free from the contact resistance effect due to the large characteristics channel length at a smaller frequency that makes the technique unique. 2-D numerical simulation with Pentacene/Ferro geometry and gold/ITO as top/bottom contact configuration has been simulated to demonstrate the concept and the model. (a) C-V without high k dielectric and without ferro, (b) C-V only with high k dielectric and (c) C-V with high k dielectric and with ferro material. • The channel capacitance of the conventional AMIS structure can be increased significantly by employing a ferroelectric material. • This property can be suitably used for extracting accurate TFT channel properties and also for sensing applications.