Low-Band-Gap Polymer-Based Infrared-to-Visible Upconversion Organic Light-Emitting Diodes with Infrared Sensitivity up to 1.1 μm

Abstract

All-organic infrared (IR)-to-visible upconversion organic light-emitting diodes (OLEDs) with an IR sensitivity up to 1100 nm were fabricated using a low-band-gap polymer as the organic IR sensitizing layer. A novel low-band-gap (1 eV) polymer, poly 4-(4,8-bis­(5-(2-butyloctyl)­thiophen-2-yl)­benzo­[1,2-b:4,5-b′]­dithiophen-2-yl)-6,7-diethyl-[1,2,5] thiadiazolo­[3,4-g]­quinoxaline (PBDTT-BTQ), with a strong photoresponse in near-IR wavelengths of 700–1100 nm was first synthesized using a thiadiazolo­[3,4]­quinoxaline (BTQ) and a thiophene-substituted benzo­[1,2-b:4,5-b2-b]­dithiophene (BDTT) as the electron-withdrawing and donating building blocks, respectively. The near-IR photodetector was then fabricated for evaluating a PBDTT-BTQ as the IR sensitizing layer. The PBDTT-BTQ IR photodetector showed detectivity greater than 1011 Jones in the multispectral region (300–1100 nm) and the maximum detectivity of 3.1× 1011 Jones at the wavelength of 1000 nm due to significantly reducing dark current (8.8 × 10–6 mA/cm2 at −1 V). Finally, the all-organic IR upconversion OLED with a PBDTT-BTQ IR sensitizer successfully converted invisible near-IR light of 700–1100 nm directly to visible green light with a peak emission wavelength of 520 nm. This is the first report of an all-organic IR-to-visible upconversion OLED with near-IR sensitivity up to 1100 nm.

Miniaturized VIS‐NIR Spectrometers Based on Narrowband and Tunable Transmission Cavity Organic Photodetectors with Ultrahigh Specific Detectivity above 1014 Jones

“…Mater. 2021, 33, 2102967 [11,13,15,18,22,27,[38][39][40][41][42][43][44][45][46][47][48][49][50][51] The performance values of the photodetectors from the literature are listed in Table S3, Supporting Information. of less than 10 −7 mbar.…”

“…D * spectra of TC-OPDs at zero bias with varied spacer (BPhen) layer thicknesses based on different active blends a) DCV5T-Me:C 60 , b) BDP-OMe:C 60 , and c) QM1:C 60 , respectively. d) Comparison of D * as a function of wavelength from previously reported photodetectors [11,13,15,18,22,27,[38][39][40][41][42][43][44][45][46][47][48][49][50][51]. The performance values of the photodetectors from the literature are listed in TableS3, Supporting Information.…”

Recent Advances in Solution‐Processable Organic Photodetectors and Applications in Flexible Electronics

“…The fabrication adaptability of OPDs enables monolithic integration of NIR OPD with visible LED for NIR visualization through NIR-to-visible upconversion. [177,178] The upconverter image sensor has been introduced in a previous review article. [179] The present review discusses the recent progress made with the upconversion devices prepared through monolithic integration of the OPD and the LED units using the solutionfabrication method.…”

Shortwave infrared-absorbing squaraine dyes for all-organic optical upconversion devices

“…A SWIR-to-visible upconversion device, also named upconversion PD [ 11 ], upconversion OLED [ 12 ] or SWIR visualization device [ 13 ], is made by integrating an SWIR PD with a visible light-emitting unit. Such devices potentially offer an alternative route to true low-cost, pixel-free SWIR imaging.…”

“…In one example, the device detected SWIR photons out to 1600 nm and the NIR photon-to-visible photon conversion efficiency (940 nm to 525 nm) was 6.5% [ 11 ]. A broad-band absorbing polymer-based PD was combined with a phosphorescent OLED and the device sensitivity extended to 1100 nm [ 12 ]. In a similar manner, an upconverter was demonstrated by monolithic integration of a low bandgap polymer:SWIR dye blend PD with sensitivity out to around 1400 nm and a perovskite light-emitting (at 516 nm) diode [ 13 ].…”