Discovering PtSe2's Potential: A New Way to Build Infrared Photodetectors

Ever heard of PtSe2? It's a two-dimensional material that's catching scientists' attention for its amazing optoelectronic properties. The thing is, when combined with bulk materials like silicon, there are often issues with defects and carrier losses. This study introduces a clever solution: using hydrophobic bonding to peel off a high-quality layer of silicon from an SOI wafer. This layer is then used to create a new type of photodetector, called a p-PtSe2/i-Si/n+-Si pin photodetector. This device can detect light across a wide range, from 532 to 2200 nanometers. Its performance is impressive, with a high rectification ratio and responsivity that remains stable even with changes in light power. The specific detectivity is also quite high, indicating excellent sensitivity. The ideality factor is close to the ideal state, and the activation energy is half of silicon's band gap, suggesting efficient carrier transport. One of the coolest things about this work is that it combines wafer bonding and 2D material transfer to create a strong, defect-free interface. This approach could open up new ways to make 2D-3D silicon-based photodetectors.