Non-dissipative internal optical filtering with solution-grown perovskite single crystals for full-colour imaging

Abstract

Herein we demonstrate that solution-grown single crystals of semiconducting methylammonium lead halide perovskites (MAPbX 3 , where MA = CH 3 NH 3 + , X = Cl − , Br − and Br/I − ) can be used as semiconductor absorbers for full-colour imaging. A one-pixel photodetector prototype was constructed by stacking three layers of blue-, green-and red-sensitive MAPbCl 3 , MAPbBr 3 and MAPb(Br/I) 3 crystals, respectively. The prototype detector was demonstrated to recognize and faithfully reproduce coloured images by recombination of the signals from each individual colour channel. This layered structure concept, besides imparting a two-to three-fold reduction in the number of required pixels, also offers several other advantages over conventional technologies: three times more efficient light utilization (and thus higher sensitivity) than common Bayer scheme devices based on dissipative optical filters, colour moiré suppression and no need for de-mosaic image processing. In addition, the direct band gap structure of perovskites results in optical absorption that is several orders of magnitude greater than silicon. This opens a promising avenue towards the reduction of pixel-size in next-generation devices as compared with conventional silicon-based technologies.

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

“…Within this approach to narrowband photodetection, it is particularly noteworthy that organic and perovskite semiconductors can be used not only as photoactive materials, but also as filter materials. This is enabled by the facile tunability of their absorption properties [83,113]. A particular implementation of this strategy involves using a filter made of a broadband photodetector with absorption (and responsivity) onset at a shorter wavelength than that of the photodetector at hand (input optical filtering with stacking) [113].…”

“…This is enabled by the facile tunability of their absorption properties [83,113]. A particular implementation of this strategy involves using a filter made of a broadband photodetector with absorption (and responsivity) onset at a shorter wavelength than that of the photodetector at hand (input optical filtering with stacking) [113]. In principle, stacking multiple broadband photodetectors along similar lines has the merit of delivering narrowband devices covering multiple adjacent spectral bands (e.g., as needed for RGB colour detection).…”

“…Notwithstanding their broadband absorption character, perovskites have been successfully harnessed (through filtered strategies) in narrowband photodetectors, thanks to their spectral tunability via facile compositional tailoring (see tables 4,6). Indeed, a central aspect of most perovskite works is the ability to tailor the photodetector passbands through the visible and the NIR range by simply replacing the halide in the photoactive material, while keeping the same procedures for material preparation, deposition, and device fabrication [28,113,116,117,119,134]. For example, in several works, APbCl 3 and APbBr 3−x Cl x (A=MA or Cs) have been used for blue-selective photodetectors due to their absorption onset in this region [28,116,119].…”

Highly Emissive Self-Trapped Excitons in Fully Inorganic Zero-Dimensional Tin Halides

“…Unlike the isostructural Cs 4 PbBr 6 ,w hich shows narrow excitonic PL only at low temperatures and at wavelengths < 400 nm, [16] Cs 4 SnBr 6 exhibits broad-band green-yellow PL at RT from STEs (peak maximum at 540 nm, Figure 1c). Upon measuring the PL excitation (PLE) and absorption spectra it was found that Cs 4 SnBr 6 resembled am olecular material with as harp excitation peak at 340 nm yielding alarge Stokes shift of about 1.2 eV (Supporting Information, Figure S4).…”

“…In (C 4 N 2 H 14 X) 4 SnX 6 (X = Br/I), [21] the addition of iodide red-shifts both the excitation and STE emission spectra. Similarly,t he PL of Cs 4 SnX 6 shifts to 620 nm (orange emission) at aB r:Ir atio of ca.…”