Emerging graphene/organic phototransistors are eye-catching technologies owing to their unique merits including easy/low-cost fabrication, temperature independent, and achieving various functions. However, their development in the near-infrared (NIR) region is experiencing a bottleneck of inferior sensitivity due to low exciton dissociation efficiency and inefficient charge extraction rate. Here, a novel-design solution-processed graphene/organic NIR phototransistor is reported, that is, creatively introducing electron extraction layer of ZnO on graphene channel and employing organic ternary bulk heterojunction as photosensitive layer, successfully breaking that bottleneck. The phototransistor exhibits a high responsivity of 6.1 × 10 6 A W −1 , a superior detectivity of 2.4 × 10 13 Jones, and a remarkable minimum detection power of 1.75 nW cm −2 under 850 nm radiation. Considering its excellent NIR detection performance, a noncontact transmission-type pulse monitoring is carried out with no external circuit support, from which human pulse signal and heart rate can be displayed in real time. The phototransistor, interestingly, can be switched into a photomemory function with a retention time of 1000 s in the atmosphere through a gate voltage of −20 V. The design takes the characteristics of graphene/organic phototransistors to a higher level, beyond the limit of sensitivity, and opens up a novel approach for developing multifunction devices.

Multicomponent systems have been widely investigated to expand the absorption spectra, ameliorate morphology and achieve high performance organic solar cells (OSCs). Here, we reveal a novel quaternary OSCs based on...

The precise tuning of the active layer morphology to improve organic solar cells (OSCs) efficiency remains a key issue in the field of organic photovoltaics. Herein, a new solution to the above problem is provided by using the dual‐solvent modulated polymer‐assisted sequential spin‐coating method. Herein, the sequential spin‐coated OSCs based on the D18‐Cl/Y6 system are prepared for the first time and an efficiency of 16.38% is obtained, similar to that of bulk heterojunction OSCs. On this basis, the performance is further improved by using a dual solvent to balance the dissolution and crystallization of D18‐Cl, separately optimizing the morphology of the donor layer and allowing the subsequent spin‐coated Y6 solution to penetrate uniformly into the D18‐Cl framework. After the dual‐solvent treatment, the D18‐Cl (CF + CB)/Y6‐based device obtains a power conversion efficiency (PCE) of 17.33% and the D18‐Cl (THF + CB)/Y6‐based device achieves an even better PCE of 17.73%. It is worth noting that no post‐treatment is adopted here and after 2500 h of placement, the efficiency of the aforementioned devices is still 90% of the original. Thus, this work provides a simple method for tuning the film morphology to prepare efficient and stable devices, which is beneficial for future commercial production of OSCs.

Semitransparent organic solar cells (ST‐OSCs) have huge potential in terms of building integrated photovoltaics (BIPVs). However, the inherent contradiction between active layer absorption and average visible‐light transmittance (AVT) hinders the follow‐up development of ST‐OSC. To solve this problem, hydrogen bond strategy has been adopted to simultaneously improve the photon trapping capability and film thickness tolerance of the devices. Here, an organic small molecule material DIBC is introduced into PM6:Y6 system to form an intramolecular hydrogen bond with Y6, through which a high power conversion efficiency (PCE) of 17.20% is obtained. It is noted that when the active layer thickness is varied from 70 to 150 nm, the PCE values distributed in the range of 16.39–17.20%, which exhibits excellent film thickness tolerance. Moreover, ST‐OSCs are achieved with a maximum PCE of 14% and a high AVT of 21.60%, which is among the best reported results of ST‐OSCs. In addition, hydrogen‐bond‐based ST‐OSCs show superior thermal and light stability in the atmospheric environment corresponding to the control devices. This work provides a feasible solution for ST‐OSC with outstanding efficiency and high AVT, which is of great significance for the industrial production of BIPVs in the future.