Near-Infrared Organic Photodetectors with Spectral Response over 1200 nm Adopting a Thieno[3,4-c]thiadiazole-Based Acceptor

Abstract

The nonclassical ten-pi-electron 5,5-fused thieno [3,4-c]thiadiazole (TTD) unit is an excellent building block for constructing sub-silicon-band gap organic semiconductors. However, no small molecule acceptor (SMA) materials based on TTD have been reported despite the fact that high-sensitivity near-infrared organic photodetectors (OPDs) are generally achieved by using SMAs. In this work, we report a TTD-based narrow band gap (0.95 eV) SMA material TTD(DTC-2FIC) 2 with strong near-infrared absorption. Employing PTB7-Th as a donor, OPDs based on TTD(DTC-2FIC) 2 exhibit an optimized responsivity of 0.095 (±0.007) A W −1 at 1100 nm and sustain a decent responsivity of 0.074 (±0.008) A W −1 at 1200 nm. Moreover, a good specific detectivity over 1 × 10 11 Jones is achieved at a wavelength of 1200 nm. Detailed characterizations imply that the performance of TTD(DTC-2FIC) 2 -based OPDs may be substantially improved by choosing lower-mixing donors with shallower energy levels. This work demonstrates that SMAs incorporating TTD as the core unit hold promise for constructing high-sensitivity sub-silicon-band gap OPDs.

Smart responsive in situ hydrogel systems applied in bone tissue engineering

“…Near-infrared (NIR) is an electromagnetic wave between visible light (VI.S) and mid-infrared light (MIR) and has a wavelength in the range of 780–2,526 nm as defined by the American Association for Testing and Materials Testing (ASTM) ( Zhang et al, 2024c ). The NIR spectrum belongs to the frequency multiplier and main frequency absorption spectrum of the molecular vibration spectrum due to the non-resonance of the molecular vibration (the molecular vibration is generated when the molecular vibration transitions from the ground state to the high energy level).…”

Fluorinated Conjugated Polymers Enabled Enhanced Detectivity in Organic Near-Infrared Photodetectors

“…Organic photodetectors (OPDs) have attracted significant interest from both academia and industry due to their excellent optoelectronic performance, solution processability, tunable response range, and large-area fabrication. − With the development of optoelectronics technology, OPDs have broad application in fields such as biomedical imaging, optical communications, and environmental monitoring. − One of the most significant advantages of OPDs is their synthetic flexibility, which allows for the preparation of different p/n-type organic semiconductors through design and combination of building blocks. This feature can be used to customize various performance parameters of OPDs, such as dark current, detectivity ( D* ), and spectral selectivity. − …”