Trap-mode PbSe mid-infrared photodetector with decreased-temperature processing method

In this paper, we investigate a trap-mode PbSe mid-infrared photodetector with decreased-temperature processing method. Usual PbSe mid-infrared photodetectors need the sensitization process requiring a high temperature of 300–600 °C in oxygen-rich and iodine-rich atmospheres, which would damage the silicon-based readout integrated circuits chip. In this work, we demonstrate a new method for PbSe sensitization at a mild temperature of 170 °C, by introducing PbI2 treated PbSe CQDs. Compared with the untreated PbSe photodetector, the response speed and the photocurrent-dark current ratio of the trap-mode PbSe photodetector are improved by 13–15 times and 2–3 times, respectively. The effects of annealing temperature, content of PbI2, and deposition time of PbSe bulk film on the photocurrent-dark current ratio and response speed of trap-mode PbSe photodetectors are also discussed.