2D Hybrid Perovskite Ferroelectric Enables Highly Sensitive X‐Ray Detection with Low Driving Voltage

Abstract

X-ray detectors with high sensitivity are of great significance in both civil and military fields. Over the past decades, great efforts have been made to improve the sensitivity in conventional inorganic materials, but mainly at the cost of increasing the energy consumption with a quite high operating voltage. Developing photosensitive ferroelectrics directly as detector materials may be a conceptually new strategy in view of the strong ferroelectric spontaneous polarization (P s ) that assists photoinduced carriers separation and transport. = 5 µC cm −2 ) is fabricated and exhibits an ultrahigh X-ray sensitivity up to 6.8 × 10 3 µC Gy air −1 cm −2 even at a relatively low operating voltage, which is over 300-fold larger than that of state-of-the-art α-Se X-ray detectors. Such a brilliant figure-of-merit is largely attributed to the superior mobility-lifetime products associated with the strong ferroelectric polarization of BA 2 EA 2 Pb 3 Br 10 . As pioneering work, these findings inform the exploration of hybrid halide perovskite ferroelectrics toward highperformance photoelectronic devices.

Durable dielectric switching and photo-responsivity in a Dion–Jacobson hybrid perovskite semiconductor

“…The band gap is estimated to be 2.50 eV by the Tauc equation. This value is comparable with those of other two-dimensional lead–bromine perovskites, such as (BA) 2 (DMA)Pb 2 Br 7 (∼2.65 eV) and BA 2 EA 2 Pb 3 Br 10 (∼2.55 eV), 34,35 and is suitable for photodetection in the visible region. Furthermore, the photoluminescence (PL) of 1 is recorded with a narrow emission peak at 510 nm (Fig.…”

2D Multilayered Perovskite Ferroelectric with Halogen Bond Induced Interlayer Locking Structure toward Efficient Self‐Powered X‐Ray Detection

“…In addition to superior X-ray attenuation and absorption, effective charge collection is crucial for sensitive detectors, which can be evaluated by the mobility-lifetime product (µ𝜏). Figure 3c exhibits a large µ𝜏 value of 2.64 × 10 −3 cm 2 V −1 , which is comparable to those of some X-ray detectors based on 2D multilayer or 3D hybrid perovskite SCs, such as (BA) 2 (EA) 2 Pb 3 Br 10 (7.6 × 10 −3 cm 2 V −1 ), [24] CsPbBr 3 (6.7 × 10 −3 cm 2 V −1 ), [2b] and Cs 2 AgBiBr 6 (6.3 × 10 −3 cm 2 V −1 ), [25] showing the great potential of BEPB for high-efficiency X-ray detectors. Moreover, large bulk resistivity is conducive to reducing the dark current and detection limit of the device.…”

Dark Current Suppression in Two‐dimensional Histamine Lead Iodine Perovskite Single Crystal for X‐ray Detection and Imaging

“…An indirect band gap structure is obtained with a band gap of 1.78 eV that is similar to the previously reported 2D perovskites. The band gap is consistent with the UV–VIS absorption test, and it is much narrower than typical 2D perovskites, such as BA 2 EA 2 Pb 3 Br 10 (2.5 eV), [ 31 ] PEA 2 PbI 4 (2.3 eV), [ 32 ] and (C 6 H 5 C 2 H 4 NH 3 ) 2 PbBr 4 (3.49 eV). [ 33 ] The average energy to produce electron‐hole pairs ( W ) can be calculated using the expression, W = 2 E g +1.43 eV.…”