Filterless Polarization‐Sensitive 2D Perovskite Narrowband Photodetectors

Abstract

with a proper selected optical filter. [8] Nevertheless, this method increases both the cost and complexity of the system and also is limited by the available filters. To address those issues, several strategies have been developed to achieve filterless narrowband photodetections, which include: (1) specially designing the absorber with narrowband absorption; [9][10][11] (2) utilizing the plasma effect to intentionally enhance the absorption at a designed wavelength range; [12] (3) engineering the charge collection efficiency via charge collection narrowing (CCN) mechanism. [13,14] In particular, filterless narrowband photodetectors based on CCN mechanism have been recently demonstrated with decent performance in both 2D perovskite single crystals and 3D perovskite single crystals and films. [15] While in 2D perovskite single crystals the narrowband photoresponse is assisted by the self-trapped states within bandgap, the band-tail states play the dominant role in 3D perovskite based narrowband photodetectors. [16][17][18] The CCN mechanism is to manipulate the charge collection efficiency to a desired spectral region so that the photo response can be controlled in the designed spectral range. In brief, the photogenerated carriers are mainly distributed close to the crystal surface for the above-gap photons due to the large absorption coefficient (termed as surface generation) while the light can penetrate deep into the crystal for the subgap photons because of the smaller absorption coefficient (termed as volume generation). The collection efficiency of surface-generation carriers is greatly suppressed due to the recombination loss due to the imbalanced carriers' transit time, higher local carrier density, and severe surface-charge recombination while the collection efficiency of volume-generation carriers is much less affected by those factors. As a result, the charge collection efficiency of volume-generation carriers is much larger than that of surface-generation carriers. For the photons with energy far below the bandgap energy of materials, the photons cannot be absorbed by the materials, and thus cannot contribute to the photocurrent again. Therefore, under such situation, only photons with energy near or slight below bandgap energy can significantly contribute to the photocurrent, leading to the narrowband spectral response. [4] Polarization-sensitive photodetectors can sense the polarization of light in addition to the intensity and wavelength of the Polarization-sensitive narrowband photodetectors can respond to a narrow spectral range of light together with the ability to sense the polarization of light. Traditionally, expensive filters combined with polarizers are utilized to realize the polarization-sensitive narrowband photodetections. To reduce the cost and simplify optical system, here a polarization-sensitive narrowband photodetector based on 2D perovskite single crystals without any additional optical components is reported. The photodetector shows a linear dichroic ratio of 1.56 at 552 nm under ...

3D‐to‐2D Dimensional Reduction for Exploiting a Multilayered Perovskite Ferroelectric toward Polarized‐Light Detection in the Solar‐Blind Ultraviolet Region

“…This work offers an efficient approach for exploring new 2D hybrid perovskite candidates toward future optoelectronic applications. [20a] GeAs, [20b] (i-PA) 2 CsAgBiBr 7 , [21] (HDA) 2 CsPb 2 Br 7 , [22] MAPbI 3 , [3a] (i-BA) 2 PbI 4 , [23] (i-BA) 2 (MA)Pb 2 I 7 [24] )a nd this work.…”

“…Its proposed that the highly anisotropic structure consisting of conductive channels and resistive hopping barriers in orthogonal orientations greatly favors the photoelectric activities along c-axis.A dditionally,t he existence of polarizationinduced electric field might benefits the separation of photocarriers and thus improves device performances in the direction of polar c-axis.F urther studies on the polarizedlight detection were performed at the angle of 08 8.P hotocurrent increased dramatically with the increasing of light intensities under polarized light of 266 nm (Supporting Information, Figure S10), giving alarge on/off switching ratio of 2.3 10 3 .T his value is comparable with other detectors based on 2D multilayered hybrid perovskites. [9] Several semiconducting materials with 2D structures,such as GeSe, [20a] GeAs, [20b] (i-BA) 2 PbI 4 , [23] and (i-BA) 2 (MA)Pb 2 I 7 (where i-BA + is (CH 3 ) 2 CHCH 2 NH 3 + ), [24] were demonstrated to be applicable for polarized-light detection in visible or infrared range,w hile our detector is sensitive to solar-blind UV radiation (Figure 4d). Notably,s olar-blind UV detectors are highly desired owing to their wide applications,including optical communications and missile tracking.…”

Optical anisotropy of one-dimensional perovskite C4N2H14PbI4 crystals

“…Though organic-inorganic hybrid perovskites possess excellent optical properties, their optical anisotropy is rarely studied. Recently, our group reported a polarization sensitive photodetector based on 2D perovskite (iso-BA) 2 PbI 4 thanks to the in-plane anisotropy, which indicates that organic-inorganic hybrid perovskites can provide the merit of excellent optical properties and anisotropy simultaneously [18]. Compared with 2D configuration, 1D perovskites have unique chain crystal structure and are believed to provide a much higher anisotropy [19].…”

3D‐to‐2D Dimensional Reduction for Exploiting a Multilayered Perovskite Ferroelectric toward Polarized‐Light Detection in the Solar‐Blind Ultraviolet Region

“…Several semiconducting materials with 2D structures, such as GeSe, [20a] GeAs, [20b] ( i ‐BA) 2 PbI 4 , [23] and ( i ‐BA) 2 (MA)Pb 2 I 7 (where i ‐BA + is (CH 3 ) 2 CHCH 2 NH 3 + ), [24] were demonstrated to be applicable for polarized‐light detection in visible or infrared range, while our detector is sensitive to solar‐blind UV radiation (Figure 4 d). Notably, solar‐blind UV detectors are highly desired owing to their wide applications, including optical communications and missile tracking.…”