Donor-Acceptor Covalent Organic Polymer Framework for High-Performance Broadband Flexible Photodetector

This paper reports a high-performance, broadband flexible photodetector (PD) based on a novel covalant organic polymeric framework material, TPATZTPA. One PD on Si-substrate and another PD on ITO-coated PET-based flexible substrate were fabricated. Both PDs exhibited a similar type of photodetection capability ranging between 350 to 950 nm. In the presence of a broadband white light source, the flexible PD exhibited a peak photo-to-dark current ratio of $18.23 \times 10^{3}$ with a bias of +2 V. Experimental results indicate that the fabricated flexible PD offers a peak responsivity, external quantum efficiency, and specific detectivity of 5.69 A/W at 570 nm, 13.06% at 565 nm, and $1.27 \times 10^{11}$ Jones at 570 nm, respectively. The transient study reveals that the fabricated TPATZTPA-based flexible PD offers a rise and fall time of 0.29 s and 0.28 s, respectively. A simple 50 cm long visible lightwave communication (VLC) system utilizing the fabricated flexible PD exhibited its efficacy by successfully demodulating intensity-modulated PN9 PRBS sequence.