All‐Polymer High‐Performance Photodetector through Lamination

Abstract

All‐polymer and semitransparent organic photodetectors (OPDs) fabricated through lamination on flexible substrates are demonstrated. Through lamination both bilayer and bulk heterojunction (BHJ) configurations for two different all‐polymer blends are easily made, and characterized in terms of detectivity, linear dynamic range (LDR), and bandwidth. These devices show high detectivity up to 1011 Jones. The importance of measured noise rather than estimated shot noise in detectivity calculation is discussed and emphasized. With this high detectivity and with the geometric flexibility due to the polymer materials, these detectors can be attached to curved surfaces for optical detection. Their use at fingertips for heart rate sensing is demonstrated. These devices also have a very wide bandwidth of more than 300 kHz and an LDR of 75 dB. As such the, roll‐to‐roll compatible lamination method shows great potential for high‐performance OPDs fabrication.

Filter‐Free Band‐Selective Organic Photodetectors

“…This agrees with the previous reports in showing that the f −3 dB in the filter-free visible-blind NIR OPDs is determined dominantly by carrier transit time. [12,40] This is reasonable because an 800 nm thick PTB7-Th visible light depletion layer, also serving as an HTL, was used in the device.…”

“…[37,38] The large area flexible OPDs can be prepared using solution fabrication processes including screen printing, ink-jet printing, and roll-to-roll printing. [39][40][41][42][43] In this work, we report our efforts to develop a novel filterfree band-selective OPD having a heterostructure photoactive layer architecture, comprising a semiconducting shorter-wavelength light depletion layer and a BHJ layer with an extended absorption to longer wavelengths. The detection spectrum window of the filter-free band-selective OPDs is determined by the difference in wavelengths between the transmission cut-off wavelength of the semiconducting light depletion layer and the absorption edge of the BHJ layer with an extended absorption to longer wavelengths.…”

Highly Responsive and Thermally Reliable Near‐Infrared Organic Photodiodes Utilizing Naphthalocyanine Molecules Tuned with Axial Ligands

“…While we have measured very low J d values in the SiNc‐OPDs, it is crucial to accurately determine the total noise characteristics of OPDs. [ 6–8,33,34 ] Figure 3c exhibits the total noise currents ( i n ) of OPDs measured as a function of bandwidth in relation with i n = [ i shot 2 + i thermal 2 + i 1/f 2 + …] 1/2 , where i 1/f is the flicker noise. All OPDs show the frequency‐dependent flicker noise component, but OPDs with SiNc‐C6 and ‐C4 still show lower noise values than the SiNc‐C3 device in the whole frequency range.…”

“…While we have measured very low J d values in the SiNc-OPDs, it is crucial to accurately determine the total noise characteristics of OPDs. [6][7][8]33,34] Figure 3c exhibits the total noise currents (i n ) of OPDs measured as a function of bandwidth in relation with…”

Narrowband organic photodetectors – towards miniaturized, spectroscopic sensing

“…Consequently, organic PDs (OPDs) have attracted much interest due to their advantageous features: OPDs are characterized by properties like lightweight, flexibility, low-cost, large-area scalability, and semi-transparency, making them potential candidates for the growing demand for smarter and safer sensors supporting daily life. [6][7][8][9] Regarding the device manufacturing, OPDs can be made by a multitude of technologies, including vacuum thermal evaporation, organic vapor phase deposition 10 or solution-based processes (spin coating, slot-die coating, 11 blade coating, spray coating, 12 inkjet printing, stamping, 13 roll to roll printing/lamination 14 ). These approaches are much easier to implement than the advanced manufacturing techniques of inorganic PDs, including high temperature and complex lithography processes.…”