High Detectivity Near Infrared Organic Photodetectors Using an Asymmetric Non-Fullerene Acceptor for Optimal Nanomorphology and Suppressed Dark Current

Recently, the development of non-fullerene acceptors (NFAs) for near-infrared (NIR) organic photodetectors (OPDs) has attracted great interest due to their excellent NIR light absorption properties. Herein, we developed NFAs by substituting an electron-donating moiety (branched alkoxy thiophene (BAT)) asymmetrically (YOR1) and symmetrically (YOR2) for the Y6 framework. YOR1 exhibited nanoscale phase separation in a film blended with PTB7-Th. Moreover, substituting the BAT unit effectively extended the absorption wavelengths of YOR1 over 1000 nm by efficient intramolecular charge transfer and extension of the conjugation length. Consequently, YOR1-OPD exhibited significantly reduced dark current and improved responsivity by simultaneously satisfying optimal nanomorphology and significant suppression of charge recombination, resulting in 1.98 × 1013 and 3.38 × 1012 Jones specific detectivity at 950 and 1000 nm, respectively. Moreover, we successfully demonstrated the application of YOR1-OPD in highly sensitive photoplethysmography sensors using NIR light. This study suggests a strategic approach for boosting the overall performance of NIR OPDs targeting a 1000 nm light signal using an all-in-one (optimal morphology, suppressed dark current, and extended NIR absorption wavelength) NFA.

Injectable Nanomedicine-Hydrogel for NIR Light Photothermal-Chemo Combination Therapy of Tumor

Traditional hydrogels have drawbacks such as surgical implantation, large wound surfaces, and uncontrollable drug release during tumor treatment. In this paper, targeted nanomedicine has been combined with injectable hydrogel for photothermal-chemotherapy combination therapy. First, targeted nanomedicine (ICG-MTX) was fabricated by combining near-infrared (NIR) photothermal reagents (ICG) and chemotherapy drugs (MTX). The ICG-MTX was then mixed with the hydrogel precursor and radical initiator to obtain an injectable hydrogel precursor solution. Under the irradiation of NIR light, the precursor solution could release alkyl radicals, which promote the transition of the precursor solution from a liquid to a colloidal state. As a result, the nanomedicine could effectively remain at the site of the tumor and continue to be released from the hydrogel. Due to the targeted nature of MTX, the released ICG-MTX could target tumor cells and improve the accuracy of photothermal-chemo combination therapy. The results indicated that the injectable nanomedicine-hydrogel system has a favorable therapeutic effect on tumors.

Morphology induced enhanced photoconductivity of a phthalocyanine-based benzimidazole linked two-dimensional conjugated covalent organic polymer

A novel phthalocyanine-based benzimidazole linked conjugated covalent organic polymer (NiPc-COP1) has been synthesized with multiple randomly ordered crystalline morphologies.