Fabrication and characteristics of back-gate black phosphorus effect field transistors based on PET flexible substrate

Black phosphorus (BP) is a layered material that is stacked together between independent atomic layers by internal van der Waals forces. In this study, we qualitatively found that the peak value of BP film with different thickness under the AFM characterization would increase with the increase of thickness, and the friction ring had a tendency of expansion. The characteristic peak within a certain range under Raman characterization will redshift with the increase of thickness, and the redshift will weaken with the continuous increase of thickness. These efforts provide the basis for selecting a suitable BP film material as the semiconductor channel for the transistor. The output characteristics and transfer characteristics of the back-gate BP field effect transistor (FET) based on PET flexible substrate are also investigated in detail. A back-gate BP FET based on a PET flexible substrate exhibits a transistor characteristic of a p-type doped ohmic contact in an output characteristic. In the transfer characteristics, the hole mobility of the back-gate BP FET device based on the PET flexible substrate was 266.6 cm2v−1 s−1 and electron mobility was 3.5 cm2v−1 s−1, and the hole mobility was 75 times that of the electron. It has a switch ratio exceeding 8.6 × 103 at the hole end. Experimental results show that the electrical properties of the device show good Schottky diode characteristics. The back-gate BP FET based on PET flexible substrate has good performance and low cost, which adds to the research and application of nano-transistor, and also contributes to the development of flexible electronic equipment.