▎ 摘　　要

In this work, we have investigated the ambient stability improvement of colloidal quantum dots (CQD) photodetectors by graphene encapsulation. The low temperature deposited graphene is performed to act as an isolating membrane between PbS CQDs and the ambient environment. The oxidization of PbS CQDs can be significantly inhibited with a graphene isolating membrane. In addition, the optoelectronic characteristics of PbS CQDs-based photodetectors encapsulated by graphene are well maintained even exposed in ambient for a month. This work paves the way for the fabrication and application of the air-stable CQDs.