Robust and flexible photodetector from a solution derived nanowire networks of organometallic charge transfer complex

Abstract

An organometallic charge transfer (CT) complex, viz, silver- tetracyanoquinodimethane (Ag-TCNQ) has been synthesized through solution self assembly. The as synthesized product characterized through scanning electron microscope (SEM), X-ray diffraction (XRD) and Raman spectroscopy indicated that highly crystalline, unidirectional, nanostructure network of Ag-TCNQ has been grown. The thin film of Ag-TCNQ based CT complex on flexible substrate exhibited excellent photoresponse characteristics under white light illumination, which is 5-fold higher than the pristine Ag nanoparticle based photodetector (PD). The modulation in photocurrent and responsivity of Ag-TCNQ PD was controlled with variation in input optical power, electrode bias and illumination wavelength. The PD displayed highest responsitivity, ca. 13.8 mA/W and photo to dark current ratio, ca. 9.2 at an optical power of 10.2 mW/cm2. The photocurrent of the device showed insignificant degradation (2.1%) when the substrate was subjected to cyclic tensile stress with bending endurance upto 500 cycles. The device also displayed outstanding opto-mechanical and optoelectronics properties by exhibiting stable, fast and reversible photo switching behavior under various tensile stress on the flexible substrate with outward bending along the conduction channel.