Solution-processable all-small molecular bulk heterojunction films for stable organic photodetectors: near UV and visible light sensing

Abstract

Organic photodetectors with solution-processed all small-molecular bulk heterojunction layers detect near UV light and are stable under high-intensity lights stronger than sun light.

Organic Photodiodes: The Future of Full Color Detection and Image Sensing

“…While many molecular materials are processed by evaporation, [ 105 ] there are examples whereby they are solution processed. [ 37,106 ] Macromolecules such as dendrimers and polymers can be processed from solution using techniques such as aerosol-jet printing, [ 107 ] spin-coating, [ 108 ] inkjet-printing, [ 109,110 ] screen printing, [ 111 ] or spray-coating. [112][113][114][115] …”

“…[ 35 ] In addition, the photodetector material plays a large part in determining the physical properties of the image sensor (fl exibility, size, and weight), which then determines the properties and applications of the sensing device. [ 36 ] Photodiodes (PDs) offer a simple device structure [ 37 ] and can essentially be grouped into those photodetectors that absorb across a broad wavelength range (broadband or panchromatic) and those specifi cally designed for color imaging in which a narrow wavelength band is targeted (narrowband or monochromatic). However, it will become apparent that these two approaches are closely intertwined.…”

Synthesis and characterization of 2,2′-bithiophene end-capped dihexyloxy phenylene pentamer and its application in a solution-processed organic ultraviolet photodetector

“…3d, cyclic voltammograms of BHBT 2 pentamer displayed three oxidation redox couples at 0.29 V (E 1/2(ox1) ), 0.81 V (E 1/2(ox2) ) and 1.07 V (E 1/2(ox3) ), respectively. 9,26 Fig. 4.65 eV and 1.96 eV with an optical bandgap of 2.69 eV as estimated from the absorption edge of the UV spectrum.…”

“…Moreover, the performance of this photodetector probably can be further improved by undergoes post fabrication annealing at higher temperature to provide better molecular ordering. 10,16,33,[41][42][43] At zero-applied voltage, the photodetector is determined to have the highest detectivity of 1.47 × 10 9 Jones under an incident intensity of 36 mW/cm 2 . By comparing the dark and illuminated J-V curves, the highest gain of this detector is about two orders in magnitude if operated at 0.2 V as the lowest dark current density appeared at this voltage instead of at 0 V. Table 2 summarizes the photovoltaic parameters and efficiency of the photodetector at zero-applied voltage under 36 mW/cm 2 AM 1.5 G solar illumination.…”

“…[1][2][3][4][5] Along this line, inorganic based ultraviolet (UV) photodetectors are the most common devices used in the field of environmental monitoring, medicine, missile plume detection and solar astronomy. [8][9][10][11][12][13][14] Besides, the comparable detectivity of organic UV photodetectors to that of the inorganic ones has granted organic based UV detectors great attraction in both academic and industrial scopes. In recent years, organic semiconductors were successfully applied in the fabrication of UV photodetectors (PDs), by which a light weight, colour selective, and flexible device can be realized.…”