Broadband Photodetectors and Imagers in Stretchable Electronics Packaging

Abstract

The integration of flexible electronics with optics can help realize a powerful tool that facilitates the creation of a smart society wherein internal evaluations can be easily performed nondestructively from the surface of various objects that is used or encountered in daily lives. Here, organic‐material‐based stretchable optical sensors and imagers that possess both bending capability and rubber‐like elasticity are reviewed. The latest trends in nondestructive evaluation equipment that enable simple on‐site evaluations of health conditions and abnormalities are discussed without subjecting the targeted living bodies and various objects to mechanical stress. Real‐time performance under real‐life conditions is becoming increasingly important for creating smart societies interwoven with optical technologies. In particular, the terahertz (THz)‐wave region offers a substance‐ and state‐specific fingerprint spectrum that enables instantaneous analyses. However, to make THz sensors accessible, the following issues must be addressed: broadband and high‐sensitivity at room temperature, stretchability to follow the surface movements of targets, and digital transformation compatibility. The materials, electronics packaging, and remote imaging systems used to overcome these issues are discussed in detail. Ultimately, stretchable optical sensors and imagers with highly sensitive and broadband THz sensors can facilitate the multifaceted on‐site evaluation of solids, liquids, and gases.

Ultraflexible Wireless Imager Integrated with Organic Circuits for Broadband Infrared Thermal Analysis

“…These NEP values and response times are comparable to those of conventional uncooled photodetectors. [ 15,40 ]…”

“…Although the connection to the switching OTFT slightly degraded the NEP, the resultant performance remained comparable to that of traditional uncooled infrared detectors. [ 15,40 ] Sensitivity can be further enhanced by integrating organic amplifiers, a topic that will be addressed in the discussion.…”

“…[ 10–13 ] These imagers feature arrays capable of adapting to objects with various shapes, enabling extensive, high‐speed imaging suitable for applications ranging from internal inspections to noninvasive medical assessments. [ 14,15 ] However, many of these imagers face challenges in detecting long‐wavelength infrared light, constrained by the inherent band structures of semiconductor‐based photodetectors. [ 16–18 ]…”

A high-performance dual-functional organic upconversion device with detectivity approaching 1013 Jones and photon-to-photon efficiency over 20%

“…2h, and an outstanding D* closely approaching 10 14 Jones was obtained at 830 nm when no bias was applied on the detecting subunit, which is one of the highest values among those reported for NIR-OPDs. [46][47][48] Meanwhile, the D* remained higher than 10 13 Jones when the bias was À0.2 V because of both the highly sensitive photoresponse and the well-suppressed dark current. The greatly superior detection performance determines the excellent electron-readout characteristics of the NIR-UCD, and is also key for realizing an outstanding photon readout.…”

Dual-benefit strategy for developing an efficient photodetector with prompt response to UV-near IR radiations: in situ synthesis and crystallization through a simple one-step annealing

“…Photodetectors are used broadly in our current society, for instance, remote controlling, on-site nondestructive biomedical sensing and imaging, night vision, and visual information processing. [1][2][3][4][5][6] Photodetectors constructed using organic compounds, nanoparticles, one/two dimensional (D) materials, and their hybrids [7][8][9][10][11][12] not only provide excellent sensing abilities but also the fascinating properties highly desirable for developing exible and wearable devices, including low-cost fabrication processes through wet chemistry, good exibility and stretchability, and even self-healing capabilities in some carefully designed materials. 2,[13][14][15] The achievements of organic electronics largely rely on lm morphologies, [16][17][18] and organic photodetectors are not an exception.…”