Fabrication of lead selenide thin film photodiode for near-infrared detection via O2-plasma treatment

By creating acceptor states in band gap of lead selenide (PbSe), oxygen can act as an effective p-type dopant and eventually invert the conductivity from n-type to p-type. Fabrication of PbSe Photodiode was thus realized by introducing oxygen atoms into PbSe thin films via O2-plasma in our research. Typical diode characteristics and splendid photosensitivity was achieved in the as-fabricated PbSe photodiode. The detectivity was determined as 1.2 × 1011 cm Hz1/2/W, 1.2 × 1011 cm Hz1/2/W and 2.2 × 1010 cm Hz1/2/W at forward bias, reverse bias and zero bias, respectively. With a response time of millisecond level, great dynamic performance was achieved via this novel fabrication process. Dimension of oxygen-doped region as well as material properties were also characterized in this research.