To achieve high-efficiency organic solar cells (OSCs) requires well balancing the trade-off between the voltage loss and photocurrent generation of bulk heterojunction (BHJ) blends. In this work, we develop high-performance...

Wavelength‐selective light detection is becoming more and more prevalent as new sectors emerge, such as imaging, wearable electronic devices, the Internet of Things, machine vision, and biosensing. Traditional narrowband RGB detection necessitates several separate devices for different colors by changing the active layer materials or applying color filters ahead of the broadband detector, which increases the architectural complexity and limits the quality of color sensing. Here, this work devises a novel dual‐mode perovskite photodetector with both narrowband and broadband light sensing based on the imbalance transportation of carriers in the perovskite: Rhodamine B (RhB) active layer. In Mode 1, under light illumination from ITO, a narrowband response in 600–700 nm is obtained with a specific detectivity (D*) of 6.7 × 1011 Jones, responsivity (R) of 7.6 mA W−1, and a full‐width at half‐maximum (FWHM) of 80 nm. In Mode 2, under light illumination from Ag, the visible broadband response of 400–700 nm is achieved with a D* of 1012 Jones and R over 80 mA W−1. Furtherly, by designing a simple optical system and signal processing, RGB light signals are detected independently and panchromatic image sensing and rebuilding are realized. This work will give inspiration to architecture design for multi‐band integrated photodetectors.

neck of the balance between photoharvest PCE and average visible transmittance (AVT). Series of strategies have been proposed to improve the PCE and AVT, such as ternary strategy with ultranarrow bandgap materials as the third component, [13] adjusting the thickness of active layers to balance the AVT and PCE, [14] adjusting the weight ratio of donor to acceptor, [15] layer-by-layer strategy, [16] and so on. [17][18][19][20][21] Besides, optimizing morphology of active layer was another efficient strategy to improve performance. Song et al. reported BHJ OPVs with PCE of 18.01% by solvent annealing. ST-OPVs were fabricated with same strategy with PCE of 13.07% at AVT of 19.33%. [7] Although the performance of opaque devices is greatly improved, the corresponding strategies applied to translucent devices have not achieved good results. The key reason is that BHJ structure requires donor (D) and acceptor (A) keeping fixed ratio, for minor adjustment of D:A ratio will have a great impact on interpenetrating networks and result in low performance. Thus, with high visible absorbance polymer donor, it is hard to realize enhancement of AVT with slight PCE loss. Promotion of BHJ ST-OPVs has fallen into bottleneck.Recently, pseudoplanar heterojunction (PPHJ) structure shows great potential application in ST-OPVs. [22][23][24][25] Donor and acceptor have gradient distribution in PPHJ structure. It was proved that PPHJ structure ensures efficient dissociation and diffusion of excitons as well as charge transporting. [26,27] In theory, slight reduction of donor thickness will get higher AVT with slight PCE loss. Hao et al. reported sequential deposition (SD) processing PPHJ ST-OPVs with PCE of 12.22% and AVT of 22.2%. [25] Their research also proved that as thickness of the active layer reduced, PCE of PPHJ devices decrease slower than BHJ devices, which means that it is valid to optimize PPHJ devices by only optimizing donor. SD is the most common strategy to form PPHJ structure. Most researchers deposit acceptor on donor film, where donor and acceptor molecular diffuse together at the interface region to form conventional PPHJ structure. [28,29] To ensure valid molecular diffusion, the solvent of top layer should have proper solubility for bottom layer. SD process is strongly affected by many factors, such Semitransparent organic photovoltaics (ST-OPVs) have great application potential in photovoltaic buildings and wearable devices. Studies have proved that power conversion efficiency (PCE) and average visible transmittance (AVT) reveal more balanced in pseudoplanar heterojunction (PPHJ) structure than in bulk heterojunction (BHJ) structure. An interesting approach named low temperature sequential deposition (LTSD)-spin-coating the small molecule acceptor (A) Y6 on polymer donor (D) PM6-is proposed to form an efficient PPHJ structure. In the LTSD process, small molecule Y6 will diffuse through amorphous PM6 layer which means that Y6 finally aggregates at the bottom of active layer and results in vertical gradient concentrat...