Study of the quasi-single crystalline lead sulfide film deposited by magnetron sputtering and its infrared detecting characteristics

Lead sulfide (PbS) detectors have the advantages of room temperature detection, high sensitivity and wide spectral application range in short-wave infrared detection (1–3 μm). Magnetron sputtering with the advantages of few impurities and precise control of film structure, compared with other preparation of PbS thin films, is a potential method to deposit PbS thin films. Silicon-based PbS heterojunction devices provide a promising architecture for infrared detection due to their CMOS process compatibility. However, there are few reports on quasi-single crystal PbS prepared by magnetron sputter and silicon-based heterojunction infrared detector based on sputtered PbS. Herein, we investigated the preparation of PbS thin films by magnetron sputtering at room temperature, studied the effect of process parameters and post-annealing conditions on the crystalline orientation and growth mechanism of PbS thin films, analyzed the surface topography, crystal structure, crystalline size and optical characteristics of films, and obtained the quasi-crystalline (200) orientated PbS films. We designed and fabricated a p-Si/n-PbS heterojunction infrared detector based on sputtered PbS films using optimized sputtering parameters and post-annealing conditions. The p-Si/n-PbS heterojunction infrared detector exhibited a high rectification ratio up to 10 4 , photo responsivity of 0.763 mA/W and detectivity of 6.07 × 10 10 cm Hz 1/2 /W.