Ductile‐Metal Ag as Buffer Layer for Flexible Self‐Powered Ag2S Photodetectors

Abstract The rigid nature of inorganic semiconductors makes them rarely use in flexible devices till now. For the first time, ductile‐metal Ag is used as buffering layer to bond the inorganic semiconductor thin films and polymer substrate forming a sandwich structure, which has outstanding flexible photoelectric character. The ductile thin Ag layer under Ag 2 S thin film acts as electrode and buffering material between the Ag 2 S and polyimide (PI) layers. The strong bonding interaction between Ag 2 S and Ag can reduce the stress force in Ag 2 S thin films that is generated during bending, which enhances its flexibility. The resulted Ag 2 S/Ag/PI film shows excellent electrical performance retentivity. After more than 10 4 cycles bending test, the conductivity of the Ag 2 S/Ag/PI films has almost not changed. The prepared Au/PEDOT:PSS/Ag 2 S/Ag/PI photodetectors are stable in air or N 2 . It can bear a small bending radius as low as 1.5 mm for ≈4000 bending cycles test without drastic performance decay. In addition, the Ag 2 S/Ag based flexible photodetectors show a wide spectral response from ultraviolet to near infrared.