Efficient Ultrathin Self‐Powered Organic Photodetector with Reduced Exciton Binding Energy and Auxiliary Föster Resonance Energy Transfer Processes

Abstract

Recent advances in organic photodetectors (OPDs) have enabled high detectivity, high quantum efficiency, and fast response, due to their broad spectral response, easy processing, compatibility with flexible devices, and cooling-free operations. The advantages of combining ultrathin and self-powered OPDs are rarely explored, as technological limitations and lack of knowledge on the underlying mechanisms may lead to low light absorption efficiency and carrier recombination issues. Here, a modification layer-assisted approach is developed to construct ultrathin self-powered OPDs with enhanced sensitivity and ultrafast response time performance due to efficient exciton dissociation, energy transfer, and charge extraction processes. Specifically, this strategy enables a reduced exciton binding energy (42.4 meV) for efficient dissociation, as well as an increased dielectric constant of the photosensitive layer that shields undesirable lattice binding effects of photogenerated excitons. As a result, a remarkable device responsivity (0.45 A W −1 ), improved response detectivity (1.25 × 10 12 Jones), and enhanced energy transfer efficiency (78.7%) are observed in the modified ultrathin organic photodetector. These findings illustrate a clear correlation between the exciton dissociation process, photogenerated exciton yields, and energy transfer channels, providing essential insight into the design of efficient ultrathin organic photodetectors.

Improved Exciton Diffusion through Modulating Förster Resonance Energy Transfer for Efficient Organic Solar Cells

“…It is evident that the increase in Y6 lifetime induced by BTA3 is comparatively lower than that achieved with Cl‐BTA3. [ 35 ] This observation suggests a comparatively lower energy transfer from BTA3 to Y6 compared to that from Cl‐BTA3 to Y6.…”

“…[28][29][30][31] FRET process plays a crucial role in mediating the efficient conveyance of energy from the excited states of energy donor molecules to the broader host system materials. This energy transfer maybe instrumental in extending the lifetime of excitons within the energy acceptor species, [32][33][34][35] facilitating more excitons diffuse to interfaces and their subsequent conversion into charge-transfer states, [36][37][38] which represents an essential prerequisite for achieving efficient OSCs.…”

Improved performance of ZnO based inverted organic photodetectors with morphological and interfacial modification

“…Therefore, the noise spectrum density ( S n ) of different devices was measured to calculate D * under −0.1 V bias by the low frequency noise test system. The specific detectivity was calculated using the following equation, 66–68 where A is the effective area of OPD, B is the normalized bandwidth (1 Hz), and S n is the noise spectrum density in A Hz −1/2 .…”

Enhancing Organic Photodetector Performance Based on PBDB-T/ITIC and GO: A SCAPS-1D Simulation Study

“…They also exhibit inherent mechanical flexibility, low-cost fabrication, good light absorption, and ease of processing, making them suitable for various applications such as imaging, communication, and medical detection [2]. Furthermore, OPDs can achieve narrowband photodetection without the need for integrating optical filters, as demonstrated by a NIR nanograting Si/organic heterojunction photodetector with a sharp response peak and fast response time, opening up possibilities for sensitive and low-cost narrowband detection in near-infrared imaging applications [7]. Additionally, OPDs can be optimized for operation under reverse bias, enabling the use of low-cost readout circuitry like CMOS for signal detection, making them ideal for continuous monitoring applications [8].…”