Ultra-sensitive polarization-resolved black phosphorus homojunction photodetector defined by ferroelectric domains

Abstract

With the further miniaturization and integration of multi-dimensional optical information detection devices, polarization-sensitive photodetectors based on anisotropic low-dimension materials have attractive potential applications. However, the performance of these devices is restricted by intrinsic property of materials leading to a small polarization ratio of the detectors. Here, we construct a black phosphorus (BP) homojunction photodetector defined by ferroelectric domains with ultra-sensitive polarization photoresponse. With the modulation of ferroelectric field, the BP exhibits anisotropic dispersion changes, leading an increased photothermalelectric (PTE) current in the armchair (AC) direction. Moreover, the PN junction can promote the PTE current and accelerate carrier separation. As a result, the BP photodetector demonstrates an ultrahigh polarization ratio (PR) of 288 at 1450 nm incident light, a large photoresponsivity of 1.06 A/W, and a high detectivity of 1.27 × 1011 cmHz1/2W−1 at room temperature. This work reveals the great potential of BP in future polarized light detection.

Anisotropic charge trapping in phototransistors unlocks ultrasensitive polarimetry for bionic navigation

“…To benchmark the figure-of-merit parameters of our OPTs, we compare them with those of the representative polarization-sensitive photodetectors in literature 16,22,[25][26][27][28][58][59][60][61][62] (Fig. 3h, more details are available in Supplementary Tables 5 and 6).…”

“…As central figure-of-merits representing polarization sensitivity, our enhanced DRs (10 3 −10 4 ) outperform the current records (10 2 , ref. [26][27][28][29] of all those photoactive material-based photodetectors, and even reaches over the extinction ratios (>10 3 ) of commercial polarizers, which is crucial for practical applications, particularly for the environments with partially polarized light (Supplementary Fig. 37).…”

“… 26 , 27 ). More recently, much improved polarization sensitivity has been further demonstrated by virtue of ferroelectrics or an external amplification circuitry 28 , 29 . Nonetheless, an effective and general strategy for anisotropic photocurrent amplification in single-component photodetectors remains elusive thus far, posing fundamental constraints to the promotion of simplified on-chip polarimetry.…”

Long-wave infrared photothermoelectric detectors with ultrahigh polarization sensitivity

“…For example, two-dimensional (2D) van der Waals materials with low-symmetric crystal structures and optical anisotropy, such as black phosphorus (BP) 12,13 , tellurium (Te) 5,14 , and palladium selenide (PdSe 2 ) 15,16 , have shown great potential in developing high-performance polarization-sensitive photodetectors, especially in the mid-/long-wave IR spectral ranges.…”

“…In general, for polarization-sensitive photodetectors, the crucial gure of merit (FoM) for polarization sensitivity is the polarization ratio (PR), which is calculated using PR = V max /V min or PR = I max /I min , where V max (I max ) and V min (I min ) represent the maximum and the minimum linear-polarization-dependent photovoltages (photocurrents), respectively. However, most of the polarization-sensitive photodetectors based on intrinsic anisotropy of 2D van der Waals materials exhibit a small PR (1 < PR < 20) 8, 12 . To further increase the PR value of 2D materials-based photodetectors, several strategies have been proposed in the past decade, including employing built-in electric eld enhanced PR by forming heterojunction/homojunction such as vertical BP homojunction (PR = 35 at λ = 1700 nm) 13 and lateral BP homojunction (PR = 288 at λ = 1450 nm) 12 , BP/MoS 2 heterojunction (PR = 100 at λ = 3.5 µm) 17 , and plasmonic nanoantenna assisted photothermoelectric (PTE) responses with con gurable polarity transition such as Gr/Au nanoantenna (PR = 1→∞/-∞→−1 at λ = 4.0 µm) 8 and PdSe 2 /Au metamaterials (PR = 1→∞/-∞→−1 at λ = 5.3 µm) 7 .…”