Enhanced IGTO TFTs via HfO₂-GPTMS hybrid insulation through optimized sol-gel

This paper presents the preparation of an IGTO TFT based on an organic-inorganic hybrid insulating layer at low temperatures (≤150°C), offering a novel approach for fully transparent displays. Through the sol-gel method, hafnium chloride (HfCl₄) and trimethoxysilane (GPTMS) were hybridized and cross-linked, forming Hf-O-Si bonds within the hybrid solution during the cross-linking process. A novel thin film material was subsequently prepared using the spin coating method. The film quality was enhanced through multiple spin coatings and thermal purification, further improving device performance. The electrical parameters of the optimal device prepared are as follows: saturation mobility (μ_sat) of 8.65 cm²/V·s, switching ratio (I_on/I_off) of 1.56 × 10⁵, threshold voltage (V_th) of 7.25 V, and subthreshold swing (SS) of 2.64 V/decade. Compared to the untreated device, carrier mobility increased by 99 %.