Efficient, Ambient‐Stable, All‐Polymer Organic Photodetector for Machine Learning‐Promoted Intelligent Monitoring of Indoor Plant Growth

Abstract

The blend ratio and thickness of the PM6:PY‐IT active layer are optimized to realize highly efficient all‐polymer organic photodetectors (OPDs). Ultralow dark current densities of less than 5.92 × 10−10 A cm−2 (at −1 V) appear when the PM6:PY‐IT active layers have thicknesses in the range of 250–400 nm and blend ratios between 1:1 and 1:1.4, suggesting a wide fabrication window. Fast rise/fall times of 560/250 ns are measured with a cut‐off frequency of 530 kHz for the OPD incorporating a 250‐nm‐thick 1:1 blend. This OPD provides superior performance, with a high detectivity of 2.98 × 1013 Jones and a wide linear dynamic range of 138 dB (at 530 nm (−1 V)). In addition, the ultralow dark current of the OPD retains excellent long‐term stability over 500 h of aging testing (thermal stress, ambient conditions, and continuous illumination). With the integration of specific light filters, a system is realized for the efficient detection of indoor plant‐growth lighting, allowing the rapid and accurate detection (>97%) of photosynthetic photon flux at various wavelengths of light that directly determine the photosynthesis and photomorphogenesis of indoor plants, supervised by machine learning. The artificial intelligence‐trained OPD effectively improves detection accuracy.

Flexible Broadband Organic Photodetectors with Ternary Planar-Mixed Heterojunction Semiconductors and Solution-Processed Polymeric Electrode

“…For the three devices, the EQE follows the same trend as the photocurrent. The responsivity of photodetectors can be calculated by EQE, according to the following equation: 13…”

“…For the three devices, the EQE follows the same trend as the photocurrent. The responsivity of photodetectors can be calculated by EQE, according to the following equation: R = E Q E × q λ h c where q represents the absolute value of the electron charge ( q = 1.6 × 10 19 C), λ denotes the wavelength of the incident light, h stands for Planck’s constant, and c corresponds to the speed of light. The calculated responsivity curves are displayed in Figure c.…”

“…Flexible photodetectors have garnered considerable attention in the realms of health monitoring sensors, flexible imaging sensors, and portable optical communication due to their exceptional wearability, portability, and even implantability. − In recent years, organic photoactive materials have emerged as highly promising contenders for flexible photodetectors due to their remarkable optoelectronic attributes, alluring mechanical flexibility, facile low-temperature preparation processability, and cost-effectiveness. − Organic photodetectors (OPDs) have demonstrated competitive performance comparable to that of low-noise silicon photodetectors across various metrics. − Furthermore, flexible organic semiconductors have emerged as favorable alternatives to inorganic counterparts in wearable electronics, facilitating the fabrication of conformal thin-film devices that adhere seamlessly to and conform with human skin.…”

Liquid–Solid Transfer Process of Ordered Structures in Efficient Polymer Photovoltaic Materials

“…Conjugated polymers possess distinctive advantages, such as solution processability, mechanical flexibility, and being lightweight, with potential applications in solar cells, , light-emitting diodes, field-effect transistors, and photodetectors. , Considerable progress has been achieved in conjugated polymer-based optoelectronic devices in recent decades. In particular, polymer solar cells (PSCs), a promising photovoltaic technology for producing renewable and clean energy from sunlight, recently reached a milestone with power conversion efficiency (PCE) over 20% and extrapolated lifetimes of >20 years .…”