Fabrication and Characterization of Lead Sulphide Colloidal Quantum Dot Photodetectors for the Near Infrared

Colloidal quantum dots are attracting a lot of interest for the fabrication of optoelectronics devices. In particular, they are suitable for simple, low cost and efficient photodetectors. Here we report on our recent results on lead sulphide colloidal quantum dot photoconductors operating in the near infrared spectral range. We describe the device fabrication process and provide an exhaustive electrical and optical characterization. The photodetectors exhibit a responsivity as high as 46 A/W and specific detectivity of about 1.7·1011 cmHz1/2W-1. Performance are investigated as a function of the voltage bias, device geometry and optical power. An evaluation of the device stability over time was also carried out.