A high performance semitransparent organic photodetector with green color selectivity

Abstract

We report a high performance green color selective semitransparent inverted organic photodetectors (OPDs) with a detectivity of 2.1 × 1012 cm Hz1/2/W at the wavelength of 530 nm which has the comparable performance to the reported metal electrode based OPDs due to low dark current density of 3.8 × 10−10 A/cm2 at −1 V. The transparent OPD showed high transparency of 26% and 60% in the blue and red regions, respectively. The relatively low transmittance in the blue region can be improved using appropriate selection of active materials which absorb only the green region.

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

“…Small-molecule semiconductors with narrowband absorption properties have played a key role in the development of organic narrowband photodetectors (see section 5.1). A significant number of them are drawn or derived from compounds originally developed as industrial colourants, laser dyes, or fluorescent probese.g., blue-absorbing coumarins [22,[44][45][46][47], green-absorbing rhodamines [44,45,[48][49][50][51] and quinacridones [11,47,[52][53][54][55][56][57][58][59][60][61][62][63], green-and red-absorbing phthalocyanine metal/metalloid complexes and derivatives [11, 44, 45, 47, 49, 54-56, 58, 61, 64-70], and green-, red-, and NIR-absorbing squaraines [23,[71][72][73] ( figure 4(b)). It is noteworthy that some narrowband-absorbing small molecules are able to form aggregates (Jand H-aggregates) featuring particularly narrow and intense absorption bands (FWHM α <20 nm, α up to 10 6 cm −1 ), a property that is very attractive for narrowband photodetection [24,[74][75][76][77][78][79].…”

“…Their outstanding electron-accepting properties in BHJs and PHJs (in combination with polymeric and smallmolecule donors alike) have led to their widespread use in all types of narrowband photodetector configurations [19,30,31,[80][81][82][83][84][85]. However, their broad absorption tail through the visible has been problematic in some configurations (see section 6.3), and this has recently prompted the development of alternative small-molecule acceptors with narrowband absorption [11,[57][58][59][60][61] or with diverse onsets [42,[86][87][88].…”

“…Going one step further in this direction, Gao et al demonstrated a FWHM EQE of 50 nm utilising a green-absorbing molecule (as a donor) in combination with transparent ZMO nanoparticles (as an acceptor), and preventing aggregation-induced broadening of the molecular absorber [131]. Narrow passbands (down to 115 nm [11]) and relatively high rejection ratios have also been enabled by donor-acceptor photoactive layers in which both components absorb in the green [11,[57][58][59][60][61]. A further successful (fullerene-free) strategy is found in the work of Li et al where a single-component green-absorbing photoactive layer was adopted to achieve a FWHM EQE of 110 nm [72].…”

Enhanced Optical Switching Characteristics of Organic Phototransistor by Adopting Photo-Responsive Polymer in Hybrid Gate-Insulator Configuration

“…Organic phototransistors (OPTs) are three-terminal organic optoelectronics with an incident light that acts as the external electrode to tune the electrical signal. OPTs not only possess the advantages of organic electronics, such as low cost and mechanical flexibility, but also an advantage of field-effect transistors (i.e., a relatively high signal-to-noise ratio) [1][2][3][4][5][6][7][8][9][10]. To fully exploit the advantages of organic devices (e.g., low cost and mechanical flexibility), it is critical to employ polymer dielectric materials as gate insulators in OPTs.…”

A route to high gain photodetectors through suppressed recombination in disordered films

“…3,4 Another advance has been the creation of narrowband detectors that use inefficient charge transport to engineer a sharp peak in external quantum efficiency (EQE) near the optical absorption edge of the active layer. 5,6 However, these designs and others 7,8 work by simply transporting the photogenerated charges through the device and have responsivities that are limited by the efficiencies of photon absorption, charge generation, and charge extraction. For photons with energies comparable to the bandgap, an absorbed photon can produce at most a single electron-hole pair.…”