Organic photodiodes: printing, coating, benchmarks, and applications

Abstract

Organic photodiodes (OPDs) are set to enhance traditional optical detection technologies and open new fields of applications, through the addition of functionalities such as wavelength tunability, mechanical flexibility, light-weight or transparency. This, in combination with printing and coating technology will contribute to the development of cost-effective production methods for optical detection systems. In this review, we compile the current progress in the development of OPDs fabricated with the help of industrial relevant coating and printing techniques. We review their working principle and their figures-of-merit (FOM) highlighting the top device performances through a comparison of material systems and processing approaches. We place particular emphasis in discussing methodologies, processing steps and architectural design that lead to improved FOM. Finally, we survey the current applications of OPDs in which printing technology have enabled technological developments while discussing future trends and needs for improvement.

Color‐Selective Printed Organic Photodiodes for Filterless Multichannel Visible Light Communication

“…Very recently, this energetic tunability allowed record efficiencies of 26% for indoor light harvesting to be reached 11. Additionally, their processability via printing techniques enables high‐throughput additive manufacturing on thin and mechanically flexible substrates with full freedom of design 12–15. Previous studies have shown that printed OPDs can compete with commercial photodiodes based on inorganic materials in terms of responsivity, dark current and linear dynamic range 16–21.…”

“…Previous studies have shown that printed OPDs can compete with commercial photodiodes based on inorganic materials in terms of responsivity, dark current and linear dynamic range 16–21. However, in their great majority, these OPDs utilize active layers developed for photovoltaic applications and are therefore designed to have a broad absorption range which aims to match the solar spectrum 14. As such, these devices have relied on device engineering approaches to limit their spectral responsivity range.…”

“…These values are among the highest values reported for solution processed OPDs particularly in the case of color‐selective devices as seen in Table S1 (Supporting Information). This case can be attributed to the favorable morphology and transport properties of the BHJ and a device design that balances transit and RC limitations 14…”

“…The device performance at lower frequencies, however, is limited by the electrical noise contributions. Typically, three sources of noise are distinguished: i) 1/ f noise, ii) thermal noise and iii) shot noise 14,50–52. While 1/ f noise is frequency dependent and is mostly dominant for low frequencies, thermal and shot noise are frequency independent (i.e., white) and scale with the device shunt resistance and dark current, respectively.…”

Rapid and high-resolution patterning of microstructure and composition in organic semiconductors using ‘molecular gates’

“…4,6 . These can be broadly classified into light-based methods such as photolithography 16 and laser-induced forward transfer (LIFT) 17,18 ; printing methods such as inkjet, vapour jet and aerosol jet [19][20][21][22][23] , and contact methods such as hard and soft imprint lithography [24][25][26] . Of these, photolithography represents the most mature technology, with a further advantage being its high spatial resolution (~1 μm in large-field proximity-mode implementations).…”