Organic-on-silicon complementary metal–oxide–semiconductor colour image sensors

Abstract

Complementary metal–oxide–semiconductor (CMOS) colour image sensors are representative examples of light-detection devices. To achieve extremely high resolutions, the pixel sizes of the CMOS image sensors must be reduced to less than a micron, which in turn significantly limits the number of photons that can be captured by each pixel using silicon (Si)-based technology (i.e., this reduction in pixel size results in a loss of sensitivity). Here, we demonstrate a novel and efficient method of increasing the sensitivity and resolution of the CMOS image sensors by superposing an organic photodiode (OPD) onto a CMOS circuit with Si photodiodes, which consequently doubles the light-input surface area of each pixel. To realise this concept, we developed organic semiconductor materials with absorption properties selective to green light and successfully fabricated highly efficient green-light-sensitive OPDs without colour filters. We found that such a top light-receiving OPD, which is selective to specific green wavelengths, demonstrates great potential when combined with a newly designed Si-based CMOS circuit containing only blue and red colour filters. To demonstrate the effectiveness of this state-of-the-art hybrid colour image sensor, we acquired a real full-colour image using a camera that contained the organic-on-Si hybrid CMOS colour image sensor.

Solution-processed semiconductors for next-generation photodetectors

“…5b), have also been implemented based on organic semiconductors [103][104][105][106] or CQDs. 44 This approach, which results in increased sensor resolution, requires a careful design in order to avoid vertical colour-crossover arising from incomplete absorption.…”

Efficiency and spectral performance of narrowband organic and perovskite photodetectors: a cross-sectional review

“…Mobility is a key determinant of the photocarrier drift length (distance travelled prior to undergoing recombination), which in turn affects the overall photoconversion efficiency. In spite of the comparatively low mobility, the charge transport properties of organic semiconductors may not pose The absorption spectra of selected organic compounds with a narrowband (C30 [22], DM-DMQA [11], ISQ [23], and U3 [24]) or broadband (PTB7-Th [25]) character. (c) The absorption spectra of representative methylammonium (MA) lead halides [26], illustrating the broadband character of these materials and their spectral tunability by halogen substitution.…”

“…For instance, for multicolour imaging applications the general arrangement involves colour mosaicisation via colour filter arrays. While effective, this approach has important downsides, e.g., spatial resolution limitations [11] and colour artifacts [12]. This has led researchers to pursue alternative narrowband strategies within the bounds of conventional semiconductor technologies.…”

Flat-Format Lens-Free Imaging Using an Organic Sensor With Guided Illumination and Application to Fingerprints

“…The prospect of available large area sensors (photodiode or photoconductive arrays) increasingly becomes a reality with the recent advent of organic photonics, itself propelled by organic light-emitting diode (OLED) applications [1][2][3][4]. Giants Samsung, Fuji and Panasonic are active in the field, press news tell.…”