Enhanced performance of near-infrared- photodetector with PbS-QD-sensitised field-effect transistor

This study investigated a method for enhancing the response speed of PbS quantum dot (QD) near-infrared photodetectors by comprehensively altering the number of QD layers and the annealing temperature of the device. The experiment found that triple QD layers annealed at 100 °C were needed to achieve the optimum overall performance in a PbS QD-sensitised field-effect transistor near-infrared photodetector. When the incident light wavelength was 1064 nm and incident light power was 4.53 × 10−5 W, the photocurrent of the device was 2.47×10−6 A, responsivity was 0.0546 A/W, detectivity was 3.71×1011 Jones, and decay time was 2.6 ms (VGS = −10 V). •Annealed improves response speed and reduces other performances.•Quantum dot layers number increasing improves all performance of photodetector.•Response speed of device (100 °C annealing, triple layer) is improved by 100 times.