Tuning electrical properties in amorphous zinc tin oxide thin films for solution processed electronics.

Area of Science:

• Materials Science
• Electronics Engineering
• Semiconductor Physics

Background:

• Solution-processed thin film transistors (TFTs) are crucial for flexible electronics.
• Tuning the composition of metal oxide semiconductors is key to optimizing TFT performance.
• Zinc oxide (ZnO) based TFTs offer potential but require performance enhancements.

Purpose of the Study:

• To investigate the effect of varying Zn/Sn composition on solution-processed zinc tin oxide (ZTO) TFTs.
• To enhance the electrical characteristics and understand charge transport mechanisms in ZTO films.
• To fabricate and evaluate organic-inorganic hybrid complementary inverters using optimized ZTO TFTs.

Main Methods:

• Fabrication of ZTO TFTs with varying Zn/Sn ratios via solution processing.
• Electrical characterization including mobility and subthreshold swing measurements.
• Low-temperature mobility studies and Kelvin probe force microscopy (KPFM) for work function analysis.
• Integration of ZTO TFTs with poly-3-hexylthiophene (P3HT) transistors to build complementary inverters.

Main Results:

• Addition of Sn to ZnO films improved electrical characteristics.
• Zn0.7Sn0.3O composition exhibited the highest mobility (7.7 cm²/Vs) and reduced subthreshold swing.
• Sn incorporation lowered activation energy and metal-semiconductor barrier, facilitating charge injection.
• Hybrid complementary inverters demonstrated a maximum gain of 10.

Conclusions:

• Optimized Zn/Sn composition in solution-processed ZTO TFTs significantly enhances device performance.
• Reduced interfacial trap densities and charge injection barriers contribute to improved electrical properties.
• ZTO TFTs are suitable for integration into high-performance organic-inorganic hybrid electronic circuits.