AlN/Ti2CO2 heterojunction photodetector with high carrier mobility and photoresponse

The AlN/Ti₂CO₂ heterostructure was investigated using first-principles calculations, focusing on its stability, carrier mobility, photovoltaic effects, and optical/mechanical properties. The results reveal that it is a type-II indirect bandgap semiconductor with a bandgap of 0.48 eV. Notably, the constructed heterostructure exhibits a smaller bandgap compared to its individual components, facilitating efficient carrier transport at the interface. Furthermore, the carrier mobility along the zigzag direction reaches 1730 cm²/V·s, while the heterostructure also demonstrates strong light absorption across multiple wavelength ranges, achieving a maximum absorption coefficient of 5.09 × 10⁵ cm⁻¹. Additionally, its extinction ratio peaks at 44.97, and it exhibits robust elastic strain resistance with an average Young's modulus of 127.24. These findings collectively suggest that the AlN/Ti₂CO₂ heterostructure holds promising potential for applications in optoelectronic devices and related fields.